Method and device for measuring in the foaming fluid

The present invention relates to a method for measuring the parameters of a sparkling liquid which, at several different levels of a liquid contained in a container, measures the magnitude Ll Z), dependent on τη of one of the parameters of the liquid. The invention also relates to a device for measuring the parameters of a sparkling liquid, such as milk and mixture, having a volume of air and at least one measuring device having several capacitance levels that can measure CI Z>, depending on a single fluid parameter. The invention is particularly applicable to the measurement of the mass or flow of a sparkling liquid such as milk.

When measuring the amount of milk in a peasant farm or dairy it is important to know its mass. Therefore, it is best to weigh the milk to determine the exact mass of the milk.

However, it is very difficult to weigh milk correctly in peasant farm barns, for example if you only need to use small, especially mobile, milk measuring devices. With this type of weighing machine, the tension effects of feed and discharge pipes, the kinetic energy of pulsating milk, vibrations due to inadequate handling, non-horizontal measuring base, cleaning problems of internal measuring chambers using reference tubes, etc. causes many problems and increases measurement errors. Therefore, it is understandable that milk quantity weighing systems can only be used in scientific research institutes, but not in everyday peasant practical work.

At present, almost all known milk measuring devices measure the mass of milk produced by measuring their thorium. There are known devices which, for example in milking machines, have receptacles for measuring the milk content or devices for measuring the amount of milk spoken. Milk flow meters that measure the amount of milk periodically or continuously depending on the load are already known.

An example of the first type of measurement is given in VFR application no. 3005489, wherein the milk is fed into a large stationary container. The stationary container is provided with a measuring probe which has a plurality of measuring electrodes arranged at the same height above each other that interact with the stationary electrode located in front of them. This method takes advantage of the property of milk that its conductivity is much higher than that of the insulator, viz air conductivity, so connecting a variable electric field to the different electrodes determines which electrodes are conductive by the resulting circuit. This baud interrogates each electrode circuit and provides an alternative solution that electrodes below the milk level give information yes, circuit connected electrodes above the milk level give information no, circuit is disconnected.

IS U.S. Pat. 35307111, which is in the field of other fields, namely oil wells, is a known method for determining the composition of various fluid media such as water, oil and gas. The measuring tube, in which the sampled sample can settle, results in three separate layers and two boundary layers due to the different densities of the materials, a common electrode and different electrodes arranged at different heights. The electrodes are cyclically surveyed using alternating voltage and their capacitance is measured. Due to the different dielectric constants of water, oil and gas, the position of the respective boundary layers and their size corresponding to their volume can be determined from the changes in the measured capacitance.

From U.S. Pat. 3370466 is also known as a method for measuring the amount of two different specific conductivity galvanic liquids in the form of liquid metals which are in layers. In the measuring vessel, several pairs of electrodes are arranged at equal distances from one another and are energized cyclically. The boundary between the fluids is determined by the change in the electrical conductivity formed between the pairs of adjacent electrodes.

IS U.S. Pat. 4450722 is also known for measuring the level of a liquid in a cylinder, wherein the opposite sides of a Light-transmitting measuring cylinder have red and green Light Sources, as well as red and green Light Receivers, at equal distances from one another. In those parts below the water level, the red component of Light is absorbed, so that only the elements that are sensitive to green become active and the so-called green signal is formed. Conversely, so-called green and red signals are formed in the parts above the water level. Thus, the appearance or disappearance of the red signal indicates that there is a water surface between these levels.

VFR applications no. 1607007 and no. 1632938 are also described for measuring milk quantities already known

Apparatus in which the milk is sprayed from the bottom upright on a perpendicular 1 curved reflective screen to provide a 360 ° milk liquid screen. Leaking milk from a certain corner area of ​​this screen is poured into a measuring cylinder. The height of the milk in the measuring cylinder is determined visually. That height is the volume of milk which corresponds to the ratio of the angle of the angular area which collects the milk to 360 °.

IS British patent no. No. 1316573, which is published in German Patent Application 2811376; 0057267 are known devices for measuring the amount of milk that is delivered periodically. The milk is poured into the measuring cup until the float on the milk surface or a sensitive milk level element at a predetermined location gives a signal. When the signal is received, the milk supply is interrupted and the measuring container spout valve is opened, through which all or part of the milk can be filled until the sensitive element at the lower level gives another signal to close the spill valve and resume milking and harvesting. into a measuring vessel.

As the volume between the upper sensitive element and the lower sensitive element is known, the total amount of milk can be determined by summing up the individual charges and assuming that the milk density does not change.

From VFR application no. 3210465 is also known as a device for measuring the amount of milk in which the milk is fed to a barrel with a predetermined cross-section outlet at the bottom. The electrodes on the inside walls of the gutter tank capacitively register the gutter height so that an appropriate amount of milk can be determined along with the cross-section of the outlet.

A similar milk flow measuring device is already known from U.S. Pat. 4452176, in which the milk is also fed into a canister from which it is discharged through a measuring slot. In this case the height of the dam must be determined to determine the flow of milk and also to measure the tanks. The disadvantage of both methods is that the mixing of the milk with the air can result in an unambiguous measurement of the height of the dam and, on the other hand, also an unequivocal measurement of the amount of milk spilled through the cross-section of the spout. over a wide range.

The problem of measuring milk volume, which has not been sufficiently evaluated so far, is related to the fact that milk is a sparkling liquid and therefore the measurement result is distorted due to the presence of foam or air particles in the milk. for example, it can be done by measuring the water content.

In particular, milk contains bound milk gases such as carbonic acid and nitrogen. They range from three to nine volume percentages. However, an even greater proportion of the gas is due to the mixing of milk with air, for example during milking. In the milking machine, the inlet air used to transport the milk in the vacuum and milk channels of the milking vessel results in a milk / air mixture of 30 to i percent by volume, depending on the milking conditions. A degassing part or a degassing vessel with a low turbulence and a sufficient surface area is required to remove air. Then, when large gas blowing at a diameter of about 3 mm increases relatively rapidly, low-air conduits, for example 0.3 mm in diameter, need to be about ten times longer. In this way, the milk volume measurement is essentially caused by a small milk flow, which is between 10 and 15% of the milk volume.

Such a small amount of feed gas cannot be properly removed from the milk by mechanical separation means, such as a receiving cyclone, filling the measuring chamber from the bottom of the S, etc., for example in small mobile peasants' milk measuring devices builds up for a short time.

However, the amount of air and the amount of purge are not always the same. They depend on many factors that cause different foam formation. These factors include milk flow rate, milk pipe channels, vacuum and milking milk channel, sucker rubber, milk pipe diameter, type of milking equipment, cow feeding that changes milk composition, udder status

The differences between cows and each individual cow, and differences depending on the lactation period of the cow.

For all these reasons, it is virtually impossible to estimate the level of milk in a milk container which is considered to be below that level of real milk, whereas the foam above that level may be overlooked as it does not constitute a significant proportion of the milk. Thus, an attempt to adjust the foam fraction by appropriate general calibration or tare will be unsuccessful, for example, with the use of small utensils primarily required for mobile milk measuring devices. When measured in containers of this size, the proportion of air in the collected liquid is often more than 30% by volume. And even in bulk milk metering devices that have recording devices for measuring sizes, depending on the height of the foam and its consistency, the foam layer can hold between 0 and 0.5 kg of milk, which is typical for milk production, for example 10 kg per milk. milking can be up to 5 X. Recording gauges typically measure along the milk / foam boundary, i.e. y.

does not estimate the amount of milk contained in the foam because of the unknown foam consistency.

From VFR application no. 2720006 is also known as a device for controlling and measuring the level of foam in a flotation device. This device provides a plurality of rod-shaped electrodes which are arranged parallel to each other in the vertical system and have their lower ends at different distances from the surface of the liquid. When the foam reaches the electrodes, the electrical circuit is connected due to the conductivity of the foam. From the amount of connected individual electrode circuits the foam level is determined. Thus, in this case, the level indication is also made from the signal type of the individual circuit switched electrodes yes / no.

Above all, milk has been referred to as a sparkling liquid. However, the same problems occur when working not only with milk but also with all other sparkling liquids such as beer, fruit juice or other technically effervescent liquids such as galvanic liquids.

The object of the present invention is the object of determining the foam profile of a sparkling liquid, i.e. determining the specific density of the liquid-air mixture in relation to the level.

Based on the measurement method mentioned above, this is according to

The present invention is achieved by measuring the specific density of different levels of foamed liquid in a base measuring section containing a degassed liquid by measuring a base measurement of CI? That, depending on whether the air-measured value <-13 is greater or less than measured value CI_q3, a relative value Cc 3 corresponding to m is drawn for each level

baseline Catraminio? of measured size CI ^? with the measurand at this level Cl 3, or the inverse of this ratio such that, if necessary, the relative number Cc'3 is formed by m

for degassed liquids, it is equal to one, and air, essentially, is zero, and that each relative number Cc, c'3 is multiplied by the value of the specific density Cp3 of the degassed rn rrj liquid.

According to the invention, this method allows the mass of a sparkling liquid to be measured by measuring its volume, since this method allows the determination of the respective proportion of the liquid at any level of the liquid-air mixture. It is possible to achieve, by appropriate selection of the instrumentation parameters, the measured relative values ​​Cc 3 equal to the desired m factors multiplied by the specific density

Cp3, the specific density value at the appropriate level would be obtained. Where necessary, simultaneous taring may be performed in the following manner to obtain a correction for the relative ratios CcO.

The mass contained in the liquid container may be determined by the relative number Cc'j being determined at each level, the m volume of liquid CY j located between adjacent levels or m

the measuring point and the bottom, so that each time a level volume CY 3, the relative number Cc ^ Z) for that level and the milk specific density Cp5 multiplied by Cc * χ px YZ) is formed, and that the liquid mass CGZ> is obtained, for all levels of CnZ>

product of the following equation:

m-1

Thus, the present invention provides a method of dividing a measured volume into layers and measuring, for each layer, the relative density of a mixture of milk and air, which merely reflects the actual milk to air ratio. At the same time, for the first time, the volume of milk in the foam can also be recorded and measured by the total milk mass.

From the above liquid equation G, it is clear that, given some assumptions, Cs-conditionsZ? by setting and processing individual measurement values, this method can be implemented in other ways, for example by reducing the time required for each overall measurement.

If, for example, it is assumed that the volume Y at each level is constant, ie equal to Y, and that m O each calibrated relative number c 'is represented by m by the ratio I' / I 'Cia I' denotes the calibrated value of m O m P denotes the calibrated initial value!), The above equation can be simplified to the following form:

^Vwhile P m = 1 m = 1

Since νθρ / Ιθ is a constant, the measurement is reduced by the sum of the assumed values ​​I 'multiplied by m factor V p / I'.

oo

If, on the other hand, it is assumed that νθ corresponds to the total volume V at all altitudes, but to size

I '+ I' +. . . +1 '

Z nn I 'o can be seen as an average of n levels calibrated by c ¹, the mass G can be determined as follows:

G = V pc¹.

It is clear that, in this case too, depending on the circumstances, a non-ratio must first be established

I '/ 1' Cm = l, ..., nZ), and the sum must first be:

n

<img file="LT3634B_D0001.tif" />

m = 1

In order to simplify such measurements as described above by selecting equal volumes V for each height level, it is best to use a cylindrical vessel with any bottom in which the height levels are equally spaced. It is clear that equal volumes νθ can also be obtained with irregular cross-sections of the vessel when the electrodes are arranged in height with respect to each other at different distances related to the cross-sectional form.

Basic measurements should be carried out on the same milk as the actual measurements to avoid, for example, differences in milk consistency or other reasons. This basic measurement may not be carried out in the main milk measuring container, but it must be guaranteed that the milk is dehumidified as well as possible, ie that there are no air bubbles.

When the base part of the measurement is not in the milk container, the measurement is complicated and it is better to perform the base measurement at the bottom of the milk container. The milk level referred to here is then assumed to reach the expected level. Under these conditions, the proper selection of vessel dimensions can help to de-air milk from near the bottom.

It turned out that measurements of i S can be made by different methods and using different milk parameters. Measurements are particularly suitable for this, in which the deaerated milk is set at a size that is at least de hundred times the same as the air. Thereafter, iS These values ​​are plotted so that the ratio of the air measured to the base measure C k or s The inverse of this value ^ is much less than the unit, while the ratio of the dehydrated milk with a base size always obtained such that it is equal to a unit.

Measurements of this type can be made using the highly variable properties of milk, which depend on the milk to air ratio, such as electrical conductivity, thermal conductivity, or the ability to absorb infrared light.

Measured values ​​may be the impedance of the measuring part when measuring the change in electrical conductivity

The amount of light when measuring infrared absorption and measuring the thermal conductivity of milk is the voltage drop across the temperature sensitive element.

In the best embodiment of the invention, the measurement deviations resulting from variations in or contamination of individual electrodes and environmental parameters can be compensated for using the same reference fluids, such as water, so that the same measurements are made at all levels. The actual measurement result is formed from the measurement results obtained from S, as well as from the measurement results obtained in the base part of the measurement, which gives the mean value and the deviations of the individual measurement parts from that mean value, and the corresponding correction factor.

Certain parameters of the measuring device can be selected so that no correction of the measured relative number c is required. In general, however, it is necessary to calibrate the type of meter once before taking measurements before taking any direct measurements. As a result, the actual measured relative number c is corrected for the specific density m of the milk-air mixture m. This, as it turns out, can in the simplest case be accomplished by the fact that, when making the adjusted relative number c ', the measured relative numbers cmm are each incremented to a degree always greater than zero. If in this case the degree indicator is determined once during calibration, it remains unchanged for all subsequent measurements.

Accordingly, the invention also provides a method for measuring the flow of a sparkling liquid, such as a flow of milk confused with air, which is, at several different levels, correspondingly measuring a dependent measure of the same parameter, the liquid in a container. the vessel is supplied with a liquid so that the liquid flows continuously through a generally vertical measuring slot so that in the basic measuring section containing the liquid, from which the gas is essentially degassed, the base measure CI ^ l is measured so that, depending on whether the measure C 1 ^ 3 in the air in question is higher or lower than the base measure, for each level

Cm3 is the ratio Cc 3 corresponding to the ratio m of the base measurement ίΙθ3 to the corresponding level Cl3 or equivalent

ΓΠ the inverse of this ratio, and that the amount of fluid flowing through the slit is determined by the equation

<img file="LT3634B_D0002.tif" />

in which the characters have that meaning; g ef f is the total mass passing through the slit

K - d χ S xp 2gd;

where d 'is the distance between the electrodes, which is the distance between the levels;

equals cm cm = 981

S Incm] - slit width; ^_ g

- specific density of the liquid;

cm n - number of electrodes;

c 'is a relative number formed at m, with a value ranging from 1 to 0;

a - Dependent on slit width, slit edge, etc. the time constant of the measuring device, which may be determined by calibration.

The method can also be used to determine the mass of the passing fluid by sequentially summing or integrating the measurement flow.

The formula is derived from the so-called Bernoul's equation such that by assuming a vertical slit of the base, the flow rate of the liquid-air mixture at each level is calculated according to the principle of hydrostatic pressure, and the pressure at the appropriate level may be calculated from the results of measurement of the foam profile, and the specific density at that level is also determined by the measurement path. It goes without saying that leaks through a certain vertical gap are just a special case and should not limit inventive ideas. By the same simple calculation, it is possible, for example, to calculate the flow rate of the sparkling liquid which flows through the opening provided at the bottom of the vessel, after which the hydrostatic pressure of this liquid can be determined by measuring the respective portion of the liquid at various levels.

The invention also provides a device for measuring a specific density of a sparkling liquid, such as a mixture of milk and air, with a vessel, as well as at least one measuring device for measuring at several levels of the vessel, depending on the same parameter in the container. a measurement that is different in that there is a predetermined base portion containing the deaerated liquid and a device that, depending on whether the measured air Cl value in the air is greater or less than the base measure obtained in the measured segment, for each level forms a relative value Cc D, m corresponding to the measured value of the basic CatraminioZ) and the inverse of this ratio, , using the above calibration, corrected for the relative number Cc '), which is equal to the unit of degassed liquid, and air is substantially zero, and a multiplication element is provided which can multiply each relative number Cc, c '5 rn m by the specific density Cpi of the degassed liquid.

This type of device may be purposefully shaped, used in a fluid volume measuring device, which differs in that it provides a calculating device

CMP3, which multiplies the relative number Cc'D of each level CnO by the specific density Cp of the vessel after the volume of liquid m m at this level and by the specific gravity Cpj of the liquid which has been evacuated. ^Cm ^x V (n ^x P&gt; that a summation device is provided for summing the products obtained at all levels to determine the total amount of liquid CGZ):

n

<img file="LT3634B_D0003.tif" />

m-1

Particularly suitable is a device, for example, for measuring milk parameters, which has an electrode at each level in the vessel and a predetermined, pre-all, counter-electrode. When measuring the change in electrical conductivity in milk as a function of the milk-air mixture, it is best to measure the electrical resistance of each part, that is, between the electrode and the general counter electrode in front of it.

To eliminate the effects of polarization, it is better to use alternating voltages. It is also expedient to insert a separating capacitor between any voltage source and the common earth electrode to remove any DC component. The oscillation frequency in the circuit could be in the range of 200 Hz to 80 kHz, preferably about 2 kHz, in order to improve the switching characteristics and prevent the drift path.

In view of the size of the air bubbles which may be present in the milk, electrodes which are generally round and have a diameter of about 0.5 to 1.2 mm are used. Studies have shown that in the presence of

For larger diameter electrodes in this range, the measurement results are more dependent on the presence of smaller diameter air bubbles, and for smaller diameter electrodes in this range, the measurement results are more dependent on the presence of larger diameter air bubbles.

Therefore, electrodes with a diameter of about 0.8 mm are best used to keep the relationship as straight as possible.

The best distance between the electrodes in height is between i and 8 mm. Particularly good results were obtained when the electrodes were spaced about 1.5 mm apart.

The smaller the distance between the electrode and the total counter electrode, the stronger the relative number variation depending on the respective measurand. Therefore, the distances between the electrodes and the common counter electrode were selected from 2 to 150 mm, and preferably from 3 to 8 mm.

In embodiments of the device in which the relative numbers are formed from electrical conductivity measurements, it has been found that the required calibration corrections for the measured relative values ​​are achieved by raising said values ​​by the same number greater than zero.

Another, most appropriate, meter of the consumption meter is equipped with an infrared source and a mirror system, which i nf rar audonasi s The beam of light can be sequentially emitted through the milk in the vessel at different levels, and optoelectronic converters are provided for all levels or , which, depending on the intensity of light received, form a measurable electrical beam.

Another consumption meter based on the measurement of the thermal conductivity of a milk-air mixture is that it has a positive temperature coefficient of temperature sensing elements arranged in different levels in the milk container Sources of temperature sensing elements with positive coefficients constantly supply them with constant power for heating, and rheostatic measuring circuits, which measure the resistance value of a temperature-sensitive element with a positive temperature coefficient as the measurand.

The invention will now be described in more detail by way of example embodiments in the drawings. In the following examples, for simplicity, only milk parameter measurements are considered. However, it is to be understood that the invention can be used to measure the parameters of any other foaming liquid.

The drawings show:

FIG. 1 is a schematic diagram corresponding to a first embodiment of measuring the electrical resistance of a mixture of milk and air; FIG. 2 is a diagram illustrating a relative number, FIG. 3 - characteristic of the relative number c (drawn in a continuous line?), Which was measured at a given time for the amount of milk in a vessel with electrodes of a given measuring system superimposed above, and a characteristic corrected after the calibration of the relative number c 'of the measuring system; FIG. 4 - a schematic diagram of a milk filling device operating in accordance with the method of the present invention, FIG. 5 is a schematic diagram of another measuring device for filling milk according to the method of the present invention, FIG. 6 is a schematic diagram of a continuous flow measuring device operating in accordance with the present invention, FIG. 7 is a graphical representation of the relationship of the relative number c 'to the individual electrode numbers over a single measurement cycle; FIG. 8 - in the same measuring cycle as in FIG.

7, but at another point in time, a graph showing the relationship of the relative number c '** to the individual electrode numbers, FIG. 9 is a block diagram of another embodiment of the invention wherein the relative number is determined optically; FIG. 10 - FIG. 9 is a cross-sectional view of a device similar to the measuring device of FIG. 9, characterized in that it employs only one light source; 11 is a measuring system shown in FIG. 10, top view, fig. 12th - a schematic diagram of another embodiment of the invention wherein the relative number is determined by measuring the thermal conductivity of the milk-air mixture.

FIG. 1 is a diagrammatic representation of a container 1 into which milk is infused continuously or discretely through the upper inlet line 2. Several separate electrically insulated electrodes E - E are arranged inside the vessel at equal distances from each other. These electrodes can also be inserted externally through the vessel wall.

The electrodes do not necessarily have to be positioned vertically above each other, but can also be arranged in a so-called thread line or otherwise with a lateral displacement relative to one another. The vessel is provided with a common counter electrode Εθ, which is opposite and equally spaced from the other electrodes. The power of the general counter electrode Εθ is supplied from the generator 4 via a voltage stabilizing circuit 5 as well as through a separating capacitor 6. Alternating sinusoidal voltage is best, but alternating triangular voltages can also be used. All electrodes E ^ - E ^ are connected via a resistor 13 to the mass. The junction points of the electrodes E - E and their 1 n resistors 13 arranged in a single row are connected to the inputs of the analog multiplexer 7. The output 8 of the multiplexer 7 is connected via an active rectifier 9 to an analog-to-digital converter 10. This converter feeds the measured size to the microprocessor 11, which on the other hand is connected to the generator 4. An indicator device 12 or a printing device is connected to the output of the microprocessor 11.

The size of the container 1 obviously depends on the amount of milk being measured. Accordingly, the tank diameter or cross-sectional shape must be selected accordingly. Since the specific density ratios of the superimposed layers are each evaluated in parts according to the invention, the volume of each layer will obviously depend on both the cross-section of the vessel and the height distance between the individual electrodes E - E in. For the sake of simplicity, a cylindrical vessel was selected in which the electrodes were spaced evenly. The electrode spacing was 1.5 mm. The electrodes were of circular cross-section with a diameter of 0.8 mm. As stated at the beginning, the bubbles formed in milk have different diameters. The amount of milk that has larger air bubbles in the foam and which is most likely to expel air or gas is relatively small. In contrast, the amount of milk that has smaller air bubbles in the foam and from which air or gas is retarded is relatively much higher. It was found that using electrodes larger than 0.8 mm in diameter produced a much stronger dependence of the measured size on very small bubbles, whereas medium or larger bubbles had practically no greater influence on the substantial variation of the measured size. In contrast, electrodes with a diameter of less than 0.8 mm were found to be more sensitive to large diameter bubbles, whereas smaller and medium bubbles produced only a small change in the measured size. For this reason, an average electrode diameter of 0.8 mm was selected, which was suitable for both small and large air bubbles.

FIG. The operating principle of the device shown is as follows.

The common counter electrode Εθ is supplied with a voltage generated by generator 4. Ideally, the voltage supplied with the oscillation frequency is 2 kHz. Feeding at much higher frequencies, such as 20 to kHz, produces a better, i.e. shorter, transient characteristic, but the amplitudes of the received measurement signals are smaller. Conversely, in the case of signals having a frequency much lower than said frequency, for example 200 Hz, the amplitudes of the received measurement signals are larger, but the transient characteristic is longer, and under these conditions drift is observed over longer time intervals. Therefore, the measurements were performed in a long-lasting mode.

The lowering rate of the natation was determined on the basis that all n electrodes should be surveyed within a time not exceeding about 0.5 second.

In addition, alternating voltages were used to avoid any polarization phenomena. For this reason, a distinctive capacitor 6 is used after the DC amplifier 5, which suppresses any DC component.

The measuring range has only an ohmic resistance. All electrodes operate in phase. The phase shift due to the distinctive capacitor acts uniformly on all electrodes due to the separation of the capacitor between the generator and the general counter electrode.

Because of the significantly higher conductivity of the milk compared to the air, the electrodes already present in the milk produce a much higher level of measurable signal than the electrodes that are practically airborne.

Each of the respective resistors of electrode E has 13 m

a measurable signal is obtained which corresponds to a voltage drop across the resistor. These measurable signals appearing at the electrodes E - E in are then read individually sequentially by a series of multiple exors 7 and fed through an amplifier rectifier 9 to an analog to digital converter 10 which then transmits the corresponding digital signals to the microprocessor ii. . The IS scans the signals received at all electrodes by a multiplexer in a shorter time, and - 26 under certain conditions - much smaller than the time between two successive milk pulses. If the nipples of the cows are milked by alternating stroke, the time difference is about 0.5 seconds. In this case, the best scan time is about 0.1 second.

The main purpose of a microprocessor is to construct a relative number c. This causes him to memorize the measurand at the beginning of the measurement. As described above, the size of the base measuring strip is the most acceptable measurement, which is measured at the lowest point, that is, a level slightly above the bottom of the measuring cup. It is then assumed that the milk which is at the lowest level above the bottom of the measuring vessel is in practice already completely degassed, ie it has no air. In this way, the measurand, which is measured at the lowest electrode, electrode E, is used as a reference. If the measured resistance is the measured resistance R, which is obtained in the 'm m measuring range between the electrode and the common counter electrode, respectively, the measured value R at the electrode E forms the BASIC measured value R_q. Since the impedance of the clean air is greater than the measured impedance of the defrosted milk under the same conditions, as a ratio c for each electrode E is the ratio mrn

If the conditions for all measurement sections and baseline are the same, then the value of the relative number c is m between (i Ctai corresponds to de-aired milk) and 0 Ctai corresponds to the measurement strip in air).

The dependence of the relative number on the measurand R is, for example, shown in FIG. 1. It should be remembered that size c 'is the relative number measured at a given level multiplied by the specific density p of the de-aired milk to determine the specific density of the foam at that level. Now, as has been found, the course of this hyperbolic curve also depends on the distance between the electrodes and the total counter electrode. When the distances between the electrodes or the measuring ranges are large, and when the useful signals are relatively small, the curve follows the curve a, whereas at short electrode distances, the characteristic corresponding to the curve is steeper. From here we can see that both curves give different milk yields

ie

b, estimates of a fraction of the foam, or also give different estimates of the air contained in the foam. Any measuring instrument must be calibrated before measuring. Therefore, in this case, it is necessary to calibrate each measuring system before its use by comparing the calculated milk mass G with the milk mass determined by the weighing method so that the corresponding measured number is corrected by the calibration results.

In general, calibration can be done as follows:

At the beginning of the procedure, one calibration sample of the same construction shall be weighed empty with the sensitive measuring elements contained therein, then filled with sparkling milk and measured with sizes I and I, giving the relative number m O c for each level m. This is then reweighed to give m the weight of the sparkling milk infused with G. This process is repeated 50 to 100 times as far as possible under different milking conditions.

The data so obtained at IS is the beginning of the relative numbers c, which are transformed, m using a known mathematical relative number c '

Būdą the method of finding and correcting so that the following reference equations are valid for all measurements for Cs):

c 'χ V, mm m- 1 - 29 - when c' = a + b χ c + dxc m mm o &lt;= c * &lt;= 1. m

Using the sequential regression analysis method,

The coefficients a, b, d, z of this general regression equation can be gradually approximated to the values ​​of the true coefficients found. This mathematical approach uses a criterion of degree of proximity, which is the mii mi zaci cation of the squared deviations between the measured and calculated milk masses.

If the relative numbers of the measurements are already in the range of 1 and 0, in most cases it is sufficient to put a = b = 0 in the equation as well as d = l and change only the size

z. The value of z, obtained from the results of the regression analysis, is between 0.33 and 3.

In the same way, the flow meter C (flow meter C), described in more detail below, can be calibrated. In addition, the mass flow rate may be determined in addition by using an additional weighing vessel for weighing. As a result, the weighing vessel is weighed in successive time periods.

Here, of course, the time delay between the respective measurements of the measuring vessel electrodes and the filling of the milk and foam mixture into the weighing vessel must be considered.

Using the measuring system shown in FIG.

whereas it has been found that the correction for the measurand 'c' can be made each time using the same degree index, which is between 1 and 2, so that it is equalized, determined by weight, milk weight by weight, milk mass. This results in adjusted, calibrated relative numbers c '. Thus, FIG. 2 curve a, obtained when the electrode spacing is 30 mm, and all values ​​of c are increased by a factor of 1.6 to evaluate the relative number c ^. In contrast, the curve b obtained with the electrode spacing 3 mm and all measured values ​​c is incremented by a factor of 1.1. That is, each time an equation is formed

Cc Z&gt; = c ', where z is the degree index, which is determined in mm by calibration.

In this way, the microprocessor determines the appropriate calibration under known conditions, the mathematical correction for each electrode E reading obtained. This relative number is multiplied by the normal milk density such that the product c'xp gives m for each level m a modified specific density equal to the fraction of air. Since, in the embodiment described, the volumes V_ between the corresponding ones are equal and approximately equal to V, then multiplying the values ​​c 'xpxV gives the mass of milk at the respective layer m level. Summing up the milk masses above each other at levels or electrodes E and E m ml at each level m from 1 to is obtained in vessel 1 -

the total mass of milk. These calculations are automatically performed by the MP microprocessor. A figure representing the total mass of milk is shown on the indicating device 12.

FIG. Figure 3 shows the dependence of the measured values ​​of the relative number "c" on the level, ie its dependence on the superimposed electrodes.

In the ordinate, individual marks denote superimposed electrodes or levels. In the abscissa, the value of the relative number c is set aside. In the embodiment described in the invention, this size varies from one to zero. The curve c shows the relative numbers, which are obtained by subtracting the measured relative numbers c by the appropriate degree index. In the curve, c '' represents milk without air, while zero represents milk without air. The curve shows that practically up to level A all the electrodes give a measurable value c '= l, which indicates that practically no air has been added to this level. In the stretch between levels A and B, the size c 'begins to differ from the unit, indicating that the milk is already confused with air in this layer. Above level B, the proportion of air increases very strongly, and above level C the proportion of milk cannot be practically measured, that is to say, the proportion of milk is very low.

In addition to measuring the mass of the milk in the collection vessel, the method of the present invention enables the appropriate milk flow to be measured and the total milk mass to be determined over the entire flow measurement.

— 32 —

To date, the above-mentioned flowmeters, which measure the flow of milk in portions, which respectively set the levels, using the first measuring electrode for pouring milk into the milk chamber and using the second measuring electrode for dispensing milk from the milk chamber, have encountered the following problem: the smaller the volume between the first and second electrodes, the more accurate the measurement of the total milk volume is in principle, since the remaining milk at the end of milking is not sufficient to operate the higher level electrode and remains unappreciated.

For example, if the electrodes between the two levels are 200 cm in volume, then this thorium will of course indicate that there may be a 200 cm error. However, if milk is poured in smaller portions, the control bodies C should be connected more frequently

3 is 6000 cm / min and the volume per serving is 200 cm, the control organs should be switched on every 2 seconds).

This means that the residence time of the milk in the measuring vessel and, consequently, the degassing of the milk by reducing the volume of the portion is becoming shorter and, at the same time, the measurement of the air content in the milk becomes increasingly inaccurate. This drawback can be completely eliminated using the method of the present invention.

FIG. 4 shows a device in which milk is measured in portions. The device 20 has a housing p

The positions marked with '* #' in FIG.

wherein the infusion chamber 22 is separated by a separating wall 23 having a spout 24 from a measuring chamber 25 below it. The infusion chamber 22 passes through the infusion tube 26 into the infusion tube 26 which passes through the milking due to milking. . Through the outlet at the bottom of the measuring chamber 25, milk is discharged from the measuring chamber 25 into the milk transport conduit 28.

The upper part 21 of the housing has a control chamber

29th The inlet chamber 22 is separated from the inner cavity membrane 30 of the control chamber 29 by a rack 31 mounted on the membrane 30, which runs down through the inlet chamber and through the measuring chamber. The lower end of the rack is made as a stopper for valve 32, which can interact with spout 27 and valve seat to close spout 27. A second valve 34 is provided in stall 31, which is below divider wall 23, which interacts with spout 24. valve seat 35. The valve pushers in the riser 31 are made such that, in the first raised position of the riser, the pusher presses the valve 34 against the valve seat 34 and closes the outlet 24, while the pusher lifts the valve 32 away from the valve seat 33 so that the outlet 27 opens. In the lower position of the rack 31, the pusher closes the outlet 27 with the valve 32 and at the same time opens the outlet 24 with the valve 34. In addition, a longitudinal axis 36 extends through a stand 31 having a first orifice 37 located below the pusher valve 32, a second orifice 38 located in the upper portion of the measuring chamber 25, and a third orifice 39 located at the top of the inlet chamber.

The control chamber 29 is connected by a tube 40 to a solenoid valve which has an atmospheric air inlet 42 on one side and a tube 43 on the other side connected to the inlet chamber 22.

The solenoid valve 4i can operate such that when the tube 40 is connected to the atmospheric air inlet 42 in the first position, while the inlet 42 is closed in the second position, the tubes 40 and 43 are connected.

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<td>it only shows</td><td colspan="2">schematically.</td>

The measuring system may optionally be directly connected to line 45, or alternatively a control circuit may be provided with a time relay 46 which controls the solenoid valve 41 via lines 47 and 48 while keeping the measuring system operable so that at each instant the amount of milk in the measuring chamber 25 is determined.

Depending on whether a control circuit with a timer is provided or a measuring system 44 which is simply connected to an electromagnetic valve, the measuring system can operate in two different ways. At first, the measurement system works as follows.

Initially, a vacuum formed during milking prevails in the milk transport conduit 28, in the continuous conduit 36 ​​with its apertures 37, 38 and 39, in the measuring chamber 22 as well as in the inlet chamber 22 and the milk delivery conduit 26. The state of the solenoid valve 41 is such that the tube 40 is connected to the atmosphere and the tube 43 is closed. Since atmospheric pressure predominates in control chamber 29 and retraction chamber 22, the rack 31 shifts against the action of the spring 49 which is within the control chamber 29 and the membrane 30 is pulled upwardly, i.e., the rack slides down to its lower end position. In this position, the valve pusher of the valve 32 sits against the valve seat 33 and closes the outlet 27, at which time the outlet 24 opens. The milk to be poured from the milk filling tube 26 to the filling chamber 22 flows directly through the inlet 24 to the measuring chamber and accumulates therein. A control scheme at predetermined time intervals selected such that, even at maximum milk flow, the metering chamber is not filled to orifice 38, the timing relay 46 is periodically switched. When the first switching signal is received, the measuring system 44 automatically detects the amount of milk in the measuring chamber 25 at a given time and memorizes the resulting parameter. The switching pulse simultaneously operates in such a way that the solenoid valve 41 switches on and interrupts the connection of the tube 40 to the atmosphere, and simultaneously the connection of the tube 43 to the atmosphere is formed. In this case, the pressures equalize between the filling chamber 22 and the control chamber 29, so that the diaphragm 30, together with the stand 31 attached thereto, is lifted upwards under the action of the spring force of the spring 49. Therefore, the rack 31 moves to the upper end position where the pusher valve fits into the seat of the valve 34 and closes the spout 24. Thus, all the milk from the milk delivery tube is collected in the delivery chamber 22. At the same time, due to the raised rack, the dispensing opening 27 is opened so that milk from the measuring chamber 25 can pass through the milk transport tube 28. Due to the continuous tube 36, even during milk dispensing, the milk is transported in your tube. 28, the metering chamber 25 and the inlet chamber 22 have the same pressure, so that the milk flows out due to its weight. At the end of the predetermined time interval, the control circuitry resets via the time relay 46 to its original state. In this way, a signal is fed to the measuring system 44, which automatically detects the residual milk in the measuring chamber 25 at a given time. This size is also memorized by the measuring system 44, and the difference between the first and second memorized values ​​gives the actual amount of milk dispensed per batch. The control pulse from the control circuit via the time relay 46 is, as mentioned, setting the first state of the electromagnet and the corresponding position of the rack 31 so that the milk in the dispensing chamber 22 can drain into the measuring chamber 25 and accumulate there. This process is then repeated until the milking process is completed. The measuring system 44 adds up the weight of the milk added at the end of each batch and at the same time determines the weight of the total milk produced.

The principle of the second mode of operation, in which, instead of a control circuit with a time relay measuring system, is directly connected to the solenoid valve 41, the principle is analogous.

However, in this case, the switching is carried out periodically at non-predetermined time intervals, but the measuring system is set up to measure at a given time the mass of milk in the measuring chamber 25 at a given time. Thereafter, upon reaching a predetermined milk mass, a corresponding switching signal is applied from the measuring system 44 to the solenoid valve 41. The milk in the measuring chamber 25 is then discharged. Even during dispensing, the measuring system periodically detects the milk mass contained in the measuring chamber 25. A new switching signal is then applied from the measuring system 44 to the solenoid valve 41 after the milk mass has been reduced to a certain size.

The outlet 27 closes again and the outlet 24 opens. In this case, the mass of each portion of milk poured is calculated from the difference in results obtained by the measuring system 44. The milk mass so measured at the end of the milking process is summed up to give the total milk mass.

Thus, according to the present invention, the metering unit measuring portions has the advantage that the loading volume does not have to be the same as in the prior art. The switching moment is determined not by the expected level of the air / milk mixture, but by the time or the actual mass of milk in the measuring chamber. It also accurately estimates the weight of the raw milk at each batch.

Finally, there is no underestimation of the part of the milk mass which, under known conditions, would be insufficient at the end of the milking process to make up the whole load, so that no control or measurement signal would be generated.

FIG. Figure 5 shows an example of another milk portioning device 50. The housing 51 is provided with a filling chamber 52 and a measuring chamber 55 below it, which is connected to the filling chamber by the inlet opening 54. A tube 53 for filling milk is inserted into the filling chamber. The passage 54 is closed from below by a barrier 56 which is formed at one end of a two-shoulder lever moving at the pivot point 57, and at the other end a counterweight 58 which holds the barrier pressed against the respective outlet 54 of the valve 59 .

The filling chamber 52 is connected by a tube 60 to a valve 61, which may consist of a solenoid valve, but is illustrated as a special stopper valve for better explanation of its function. The valve 62 is connected to the measuring chamber 55 by a tube 62.

In addition, position 63 is a milk transport tube through which milk is drawn out from the suction booth. The milk transport tube 63 includes a tube 64, the other end of which is at the bottom of the measuring chamber, in a recess 66. At the very end of the tube 65 is a non-return valve having a ball 58 shape which fits under its own weight to the valve seat 67.

Finally, the filling chamber 52 is also connected to the milk transport tube 63 by another tube 69.

The measuring chamber, as well as the apparatus described above, is provided with a plurality of measuring electrodes E - E, which are located in front of the general counter

electrode E. The electrodes are connected to a measuring system 74 which corresponds to the measuring scheme shown in FIG

1. The measuring system is connected to a valve 61 by an electric rice line 70, if the valve is of the electrical type, or is connected to an actuator not shown in the drawing, in the case of a mechanical valve.

The operating principle of this unit is as follows.

Initially, the filling chamber 52 and the metering chamber 55 are subjected to a vacuum formed during milking via a tube 69 or 64. The milk poured into the filling chamber through the filling tube 53 by its own weight opens the closure barrier 56 and thus enters the measuring chamber 55. The measuring system 74 measures the milk in the measuring chamber 55 at short intervals. If iS predefined is available -

The size of this measurable milk mass, the line 70 to the valve 61 delivers a trigger pulse. The valve 61, which initially forms the connection between the conduits 60 and 62, is switched by this actuation pulse such that the conduit 60 closes and the conduit 62 engages with the aperture 71, i.e., the atmosphere. In this way, while the filling chamber 52 is still exposed to the vacuum created during milking, the pressure in the measuring chamber 55 is increased to atmospheric pressure. The vent damper 56 then presses against the valve seat 59 and at the same time closes the outlet 54- Thus, from this point in time, milk is collected in the filling chamber 52.

At the same time, the milk in the measuring chamber 55 is subjected to a pressure difference which occurs, on the one hand, at atmospheric pressure in tube 62 and, on the other hand, in the vacuum formed in tube 64, which prevails during milking. Due to the difference in pressure, the milk in the measuring chamber 55 is drawn out through the tube 64 when the non-return valve 67, 68 is opened. At this point in time, the measuring system 74 determines the mass of milk in the measuring chamber 55 within a short time. As soon as the milk is completely withdrawn or as soon as the milk mass to be measured reaches a predetermined amount, the measuring system 74 delivers another control signal to the valve 61, which returns the valve to its original state. Therefore, the pressures in the filling chamber 52 and in the measuring chamber 55 are equalized through the connected tubes 60 and 62. In this way, the milk from the filling chamber 52 can enter the measuring chamber again through the non-venting barrier 56

55, and the process is repeated as described above.

The non-return valve 57 and 58, which is provided in the tube 64, prevents possible milk in the tube

64, return to measuring chamber 55.

FIG. Fig. 6 shows an example in which milk flow can be measured practically continuously, so that by summing the milk flow curves at certain points in time, the total milk mass obtained during the milking process can eventually be measured.

The device is shown schematically so as not to deviate from the main spirit of the invention.

The general housing 80 is provided with a filling chamber 81 into which milk is poured tangentially through the filling tube 82 so that its mixing is significantly reduced. The filling chamber 81 is separated by a baffle wall 83 from a measuring chamber 84. The separating wall 83 between its underside and the bottom 85 of the body 80 and, if necessary, the side walls has a passage 86 for milk to pass through.

The amount of milk flow through the slit or through the wall into the measuring chamber 84 is limited to further inhibit milk mixing. There is also an opening 87 between the upper partition wall 83 and the housing, which allows the pressures between the chambers to be continuously extended.

The measuring chamber 84 is provided with a closed and open tube 88 having a lower portion 42 extending from the bottom 85 of the measuring chamber 84. The tube 88 has a longitudinal recess 89 in the sidewall extending to the bottom of the measuring chamber. Within the tube 88, another tube 90 is provided coaxially spaced apart, the lower end of which is open. The other end 91 of that tube is connected to a milk transport pipeline, not shown in the drawing, which is usually dominated by a vacuum formed during milking. Near the slit 86, electrodes E - E are installed at various levels. There is a common counter electrode Εθ at some distance from 1 2 of these electrodes. Preferably, the common counter electrode Εθ is located outside the tube 88, although FIG. 6 shows that it is mounted freely.

Electrodes E - E vra connected to measuring system iz '

94, the diagram of which is the same as that shown in FIG. 1.

The longitudinal notch 89 has the same width S throughout its length. The milk flow meter operates as described below.

Dairy milk passes through the dosing tube 82

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transport tube.

In another embodiment of the invention, instead of the milk outlet pipe 90 going up, it runs down the pipe 92, which is connected to the milk transport pipeline through the open lower portion of the pipe 88.

In successive short time intervals, the relative numbers c for each level or corresponding electrode at that level are respectively set. Then, based on those relative numbers at a given point in time, for all levels i to n, the effective change in milk mass per unit time can be calculated accordingly using the following mathematical formula:

<img file="LT3634B_D0004.tif" />

in which the characters g eff have the following meaning:

- total mass passing through the slit;

K = dx S χ p 2gd;

where d [cm] is the distance between the electrodes equal to the distance between the levels;

cm = 981 -;

S

S [cm] - slit width;

cm

- specific gravity of the fluid;

nc 'm

cm number of electrodes;

level m is a ratio number ranging from 1 to 0;

a - Dependent on slit width, slit edge, etc. the time constant of the measuring device, which may be determined by calibration.

Since the microprocessor MP as shown in FIG. 1, is programmed such that it computes and memorizes m for each measured number c by this formula

The change in the amount of milk per unit time allows the milk flow to be determined at certain points in time. Delaying the milk flow values ​​over a defined time interval would give a known time-response curve for milk flow in the milking process. Summing up all the measured quantities of milk flow multiplied by the length of successive time intervals gives the total quantity of milk produced.

Calibration of this embodiment was performed in exactly the same manner as that of the embodiment explained in FIG. 1, that is, the actual amount of milk measured during one milking cycle was weighed and the relative numbers were adjusted accordingly. ' It appeared that the measurement results thus obtained were well matched with the milk yield determined by comparison, so that each time the relative numbers c were measured, m was respectively increased by one and the same degree index, which is in the interval between one and two. You only need to perform this calibration once. After that, the parameters of all measurements, even other cows, other feeding conditions, etc., remain constant.

According to an embodiment, the volume of the container for collecting milk to a certain height was 35 cm and the height of the container was 12 cm. The height between the individual electrodes in terms of height was approximately 1.5 mm. The total number of electrodes positioned one above the other was 64. The distance between the electrodes and the common counter electrode was 3 mm.

The width of the longitudinal slit was 3 mm.

The simplified measurement of the milk quantity may also be carried out in such a way that the opening of the bottom of the measuring vessel may be a calibration orifice, during which the hydrostatic pressure of the milk is continuously measured by measuring the milk mass above that level.

As explained in the embodiment shown in FIG. 1, it is preferable that the base measurements be made near the bottom of the measuring vessel. Usually with the normal milk flow at the beginning of the milking cycle, the bottom and the first measuring electrode are exposed to the milk almost immediately after milk delivery. A small amount of air is removed relatively quickly. This is a baseline measurement practically in a short period of time that corresponds to the state in which the milk is evacuated. However, it may happen that air may be introduced due to a poor connection of the vacuum or milk transport pipelines, or because the milk contains more air at the beginning of the milking cycle than should be present in the defrosted milk. Only to avoid such cases, the microprocessor is programmed in such a way as to memorize initially the basic fixed measurement obtained from the previous measurements and used in the initial part of the measurement to form relative numbers c '. Along with this value, an adjustable base m is measured at the base measurement site and the result is compared to a fixed base measurement. As soon as the actual measured base value at least achieves a 35 Z fixed target base measure, a switching is performed to measure the actual base measure. Nevertheless, the actual base measure is also compared with the original fixed base measure. If, during the measurement, a significant change in the actual base measure that exceeds% of this value is obtained during the measurement, it automatically switches back to the fixed base measure. In this way it is possible to achieve reliable measurement even when working under very unfavorable conditions of the air / milk mixture ratio, which can occur, for example, in the case of extremely high flows, very intense mixing of milk and air, and the presence of long milk in the measuring chamber cannot practically be de-aired, or which may

-appear at the end of the milking cycle, because then the same amount of air mixes with the decreasing amount of milk.

FIG. 7 and FIG. 8 shows graphical instant blows. profile images of milk flow at different time points in the same cow milking cycle. The graphs show the relative numbers c 'in the abscissa axes, respectively, while the ordinate axes show the numbers of the electrodes in the offset relative to each other in spaced intervals. The graph shows 64 electrodes. As mentioned. previously, the total read time for all electrodes is approximately 0.1 s. As can be seen from FIG. 7, the value of the relative number c '' of the electrodes to the tenth digit is about a unit. That is, up to that level is pure or, in other words, degassed milk. In contrast, the measuring electrodes above, i.e., from the tenth to the forty electrodes, have a relative number different from the unit.

In the measurement results shown in FIG. 8, only the lower electrodes themselves give a measure of the relative number c ′ * per unit. The measuring electrodes above, i.e., the fifth to sixty electrodes, respectively, indicate a size smaller than a unit.

FIG. 7 and FIG. The curves shown in Fig. 8 show very clearly that in no way can the measurements of milk froths be overlooked, as has been the case until now with this type of device. If both curves where they reach c '= 0.9, a cut would be made along the line D or D', ie in places where the proportion of liquid in the foam can be assumed to be approximately equal to the amount of liquid already exchanged in the milk portion below the separation line D or D, this becomes a clear difference in the proportion of milk in the foam.

For both curves, the milk mass flow rate through the slit below the separation line D or D 'is up to

1.53 kg / min. The foam above the separation line D or D 'has a particularly different milk mass.

Therefore, FIG. In the foam 7, the milk mass in the stream is only 0.37 kg / min, whereas in FIG. The milk mass contained in the comparative foam profile in the milk flow is 0.97 kg / min.

FIG. Fig. 9 shows another embodiment of the device according to the invention, in which the measurand in the measuring section is not the impedance of milk, but light transmission at predetermined levels.

The raised milk is directed, for example, into a transparent infrared measuring chamber and either collects therein or accumulates in the measuring system shown in FIG. 8. Several light sources C LEDs JL - L are arranged at different levels on one side of the measuring chamber. Measuring chambers 100 at the appropriate levels of 1 n are equipped with photodiodes D - D directed at these LEDs. The LEDs are all controlled together by the circuit 107 or the LEDs are controlled sequentially by successive multiplexers 102 '.

Photodiode D - D through electrical resistors C resistor) in

W - W are connected to mass 101. The resulting drop in voltage across ln resistors can be read by multiplexor 102. Multiplexer 102 is synchronized with a corresponding multiplex exterior 102 'in the appropriate bed. The output of the multiplexer 102 via the amplifier 103 is coupled to an analog-to-digital converter 104, the digital signal of which is fed to a microprocessor 105. Using a microprocessor, the result of the measurement can then be displayed on the indicating device 106. Successive measurements can be made microprocessor-wise, as the respective signals are fed through line 108 to the multiplexer 102 'or to the master circuit 107 107.

The operating principle of the measuring device is as follows.

At a given point in time, microprocessor 105 supplies a control signal to a control unit which, by its appropriate connection, supplies voltage to the LEDs LL. At the same time, a start n signal is applied to the multiplexer 102 'via line 108. It turns on the LEDs in turn for predetermined time intervals (talking about the LEDs that are emitting infrared light)

L - L in radiation mode. The light is absorbed by the mixture of milk and air, respectively, in the measuring vessel 100 at the measuring point between the LEDs L m

and the corresponding photodiode D. If there is only air, the amount of light emitted to the corresponding photodiode in m is higher than in the case of pure milk. Depending on the respective light intensity incident on the photodiode it generates a current which in the corresponding resistor W m

produces a corresponding voltage drop across mass 101.

As the multiplexer 102 operates synchronously with the multiplexer acute 102 ', the voltage drop across resistor W m

is measured at the same time that the corresponding LED L is illuminated. Measure voltages accordingly i

1, the drops are fed through a multifunctional exor 102 and an amplifier 103 to an analog-to-digital converter 104, and from there to a microprocessor 105 in digital form.

accumulates measurable voltage drops or voltages in Lee

U. As with the measuring system shown in FIG. n the measurand measured above the bottom at the first level of the measuring vessel 100, that is, in the measuring part between the LED L and the photodiode D *, is received and stored as the base measurement U = θθ. The ratio is then formed in the microprocessor for each part of the measurement at each level from l to n, respectively

Mi k coprocessor

These relative quantities are the relative numbers c described above. Further processing of this relative number and measurement of milk volume or milk flow is performed in the same manner as in FIG. 1.

FIG. 10 and 11 show an embodiment in which the LED system C has light sources? L - L, ln leaving the other part of the unit intact, is replaced by one light source. Shown in FIG. 10 and FIG. Embodiment 11 is intended only to excite sequential light signals at individual levels, which are then received by photodiodes D - D after passing through measuring chamber 100.

in

For example, FIG. 11 a measuring vessel can be seen

115, in which a tube 116 is inserted vertically and a vertical notch 117 is made therein. This tube 116 discharges milk which passes through another tube which is not shown in the drawing. The measuring vessel 115 has a liner of a conductive material such as a fill level indicator. The opposing side walls 118 and 119 respectively limit the portion of the milk measurement. Under the sidewall 119, photodiodes DD are disposed relative to each other at an appropriate height, as can be seen in FIG. 10. Above the measurement

The cameras are a laser 110 whose beam passes into the rotating mirror 112. The actuator 113 can rotate the rotating mirror 112 at an angle. Below the rotating mirror 112 and the laser 110 is provided a reflecting surface 114 which is part of the parabolic mirror. This reflecting surface 114 is made such that the focal point of the parabolic mirror 114 is at a point on the rotating mirror 112 at which the laser beam 121 falls. Therefore, the laser beam 121 bends depending on the position of the rotating mirror 112 in different directions, for example, according to the shown beams 123, 124 or 125, which, when reflected from the parabolic mirror, bend as parallel beams at respective levels h, h and h, respectively. . That is, a rotation of 1 mn of a rotating mirror 112 can successively produce a corresponding beam of light at individual levels. The light emitted by the appropriate level of photodiode D - D is then received in the appropriate part of the measurement by the absorption or scattering of the beams.

in

Further processing of this signal is performed by the measuring and switching devices as shown in FIG. 9th

C At the mirror system, light 1 at different levels can be supplied by a light feed system made of fiber optic}.

FIG. Figure 12 shows an embodiment in which the air in the milk changes the thermal conductivity of the mixture so that an appropriate milk to air ratio can be determined by measuring the thermal conductivity.

The measuring vessel 130 contains temperature sensitive elements having a positive coefficient of temperature at certain heights above each other. They are connected to stable current sources 132, which heat the temperature sensitive elements and whose heating power - 53 - can be regulated by the elements 138 and 139. Each temperature-sensitive element with a positive temperature coefficient stabilizes the temperature read out by the multiplexer, and the received signals are fed through an amplifier 134 and an analog-to-digital converter to the microprocessor 136. The measurement result can be displayed in indicator 137- , control can be performed by a microprocessor 136.

The device operates such that the superimposed current from 2 to n of the temperature sensitive elements above each other is controlled by the elements 138 and 139. whereas the temperature sensing element with a positive temperature coefficient is applied to the first, which is at the first level or near the bottom of the measuring vessel. without giving up. When the heating current is switched off, the temperature of said element is measured by measuring its resistance. The IS resistance is calculated by calculating the corresponding temperature of the sensitive element. This temperature is compared with the temperature of the temperature-sensitive element -1. The measured temperature according to the impedance obtained is compared with the temperature that the temperature sensitive element had to heat. The relative number c for each temperature-sensitive element at each level can then be determined as described above.

in a vessel, measure the volume of each layer between the levels and calculate the mass according to