SU120031A1 - A device for determining the acidity of milk by its density - Google Patents

Description

Instruments are known for determining the acidity of milk by its density, made in the form of a transparent vessel for the test sample and controlling the transparency of this sample sensor.

The described device allows reducing the laboriousness of testing for the maximum acidity of a sample of milk mixed with a reagent that changes the color of the milk depending on the acidity.

The essence of the invention is that a cylinder of a manual piston pump connected by pipelines with valves to a tank for milk and a reagent and with a drain pipe for a spent sample is used as a sample vessel.

In the bridge circuit, a lamp relay is used, which switches the signal lights and the actuator serviced by this device with its contacts.

The device is equipped with a relay connected in parallel to the sensor's illumination lamp, which is triggered when it blows and is os11, which activates an alarm device with its contacts.

The drawing shows a device that contains a transparent vessel 1 for placing a test sample in it, made in the form of a cylinder with pressure 2, connected by pipelines 5 with a milk reservoir, a reagent tank 5 and a nozzle 6 for draining the spent sample; pipelines 5 are equipped with valves 7, 8 and 9.

The transparency of the sample is monitored by a sensor consisting of an illumination lamp 10 and the compensating photoresistance P illuminated by it and through the vessel / with the breakdown of another photoresistance 12. embedded in the shoulder bridge circuit.

When pressing the handle J3, the pistol 2 goes down and pushes the milk in the vessel /, through the drain pipe 6, opening the valve 7 by pressurizing the liquid; wherein the valves 8 to 9 are closed.

No. 120031-2 -

When the knob 13 is released, the piston 2 under pressure of the spring 14 returns to its original position, creating in the vessel / vacuum.

As a result of the vacuum in the vessel (under the pressure of the milk and the reagent), valves 5 and 9 open. The milk and the reagent flow through the mixer (5) into the vessel /. The required dosage of the volumes of the milk sample and the reagent is regulated by the weight of the valves 5 and the diameters of the metering ports 16 and 17. The reagent is I1, with phenolphthalein; the reagent concentration must correspond to a given value in degrees Turner.

The main optical channel serves to create the light flux passing through the mixture, which is in a transparent vessel I, and contains lenses 18, 19, 20, 21 and 22 and a light filter 25.

The second optical channel serves to illuminate the photoresistance llj designed to stabilize the operation of the device, in order to increase its accuracy when the brightness of the illumination lamp 10 changes. The second optical channel contains a lens 24 and an attenuating optical filter 25.

The aplanatic lens 18 serves to increase the light flux in the optical channel, and the lenses 19 and 20 to create a narrow light beam passing through the mixture in the vessel. Lenses 21 and 22 are designed to concentrate the light flux in the pupil of the photosensor.

The power supply of the bridge circuit is carried out from two special power sources, of which one feeds the anode circuit of the circuit and the second is fed to the cathode of the electron tube 26 to compensate for the potential on the grid created by the photoresistors J} and 12 and the resistances 27 and 28.

Using variable resistance 28, the circuit is tuned so that when the acidity of the milk is equal to the specified limit value, the electronic lamp 26 remains closed. When the magnitude of the compensating resistivity changes, the potential on the grid of the electron tube 26 changes under the action of a change in the spectral characteristics and density of the mixture. This change occurs in such a way that when the acidity of milk is greater than the limit, the potential on the grid decreases and the electronic lamp 26 remains closed. When the acidity of the milk is less than the limit, the potential on the grid exceeds the threshold to lock up, and the electronic lamp 26 opens.

The anode circuit of the electron tube 26 includes a winding of the relay 29 and a resistance 30. The anode of the lamp is blocked by a capacitor 31. The contacts of the relay 32 are used to switch signal lamps 33 and 34, and the contacts 35 are used to switch command circuits. The signal light 33 signals the acidity value, less than the limit value, and the light bulb 34, the value of acidity that exceeds the limit value. Resistance 30 and capacitor 31 provide a clear operation of relay 29. Power is supplied from an AC mains with a frequency of 50 Hz and a voltage of 127, 220 V using transformer 36. The transformer is switched by switch 37, and the device is switched on by switch 5S.

Semiconductor germanium diodes 39, 40, and 41 are used as rectifying elements. Small electrolytic capacitors 42, 43, 44 are used in filter circuits. Resistance 45 serves to limit the grid currents of the electron tube 26, and resistance 46 to equalize the compensating potential at the cathode. electronic lamp during operation of the circuit. The lighting lamp 10 is supplied from transformer 36 through resistance 47. To eliminate spurious signals when lamp fails, a relay 48 is used with a diode 49, a capacitor 50 and resistance 51.