RU6628U1 - INDUSTRIAL PH METER WITH STERILIZABLE SENSORS FOR FOOD - Google Patents

Abstract

An industrial pH meter with a sterilizable sensor for food media, comprising an immersion sensor with a measuring glass electrode for determining pH and an auxiliary reference electrode installed in the sensor housing, as well as a high-resistance transducer for measuring the emf of the glass and auxiliary electrodes, characterized in that the composition of the sensor additionally introduced a temperature sensor for measuring temperature, a measuring glass electrode is made with a solid electrolyte from an alloy with a carrier of hydrogen ions, and an auxiliary The reference electrode is made on the basis of a non-flowing polymer electrolyte, while the electrodes and the temperature sensor are sealed in the sensor case using silicone sealant and a rubber gasket, in addition, the high-resistance converter additionally includes an integrated programmable controller that automatically converts the measured pH value to 20С and recounts pH in titratable acidity.

Description

INDUSTRIAL pH METER WITH STERILIZABLE SENSOR FOR FOOD

Industrial pH meter refers to measuring instruments of the food industry and can be used to control the acidity of dairy products in tanks and pipelines.

Closest to the claimed device is a pH meter-202.2, including a tubular body, a holder, an immersion sensor with a measuring glass electrode for determining pH, an auxiliary reference electrode, and a high-resistance transducer for measuring the electromotive force (EMF) of the glass and auxiliary electrode. (L.P. Brusilovsky, A.Ya. Vainberg, Automated Process Control System for Whole-Dairy and Canned Milk Production Handbook, M. Kolos, p. 280, 1993)

However, the design of the sensors of this device has drawbacks, namely, it does not allow its use for technological processes requiring sterilization of sensors with hot water and steam (up to), since electrodes with liquid filling are used. In addition, the high accuracy of measuring the acidity of dairy products by a high-resistance transducer and the tightness of the sensor at the junction of the housing with the electrodes are not ensured.

The technical result of the proposed solution is to create an industrial pH meter with a sensor that can withstand high temperature

Object - utility model MPYU G01 N33 / 04

processing during sterilization, as well as with a high-resistance converter, which allows to increase the accuracy of control of the acidity of dairy products.

The technical result is achieved in that in an industrial pH meter with a sterilizable sensor for food media containing an immersion sensor with a measuring glass electrode for determining pH and an auxiliary reference electrode installed in the sensor housing, as well as a high-resistance transducer for measuring the emf of the glass and auxiliary electrodes, according to the claimed solution, the sensor composition additionally introduces a temperature sensor for measuring temperature, the measuring glass electrode is made with solid electrolyte m alloy with hydrogen ion carrier, an auxiliary reference electrode is formed on the basis of non-flowing polymer electrolyte, wherein the electrodes and the temperature sensor in the sensor housing is sealed with silicone sealant and rubber gaskets. The high-resistance converter additionally includes an integrated programmable controller that automatically converts the measured pH values to the nominal temperature, for example, 20 ° C and converts the pH values into titratable acidity values.

Figure 1 shows the design of the sensor device. The main structural parts of the sensor are 11, the tubular body 1 and the holder 2, in the latter a measuring electrode 3, a reference electrode (4) and a temperature sensor 5. are fixed in silicone sealant, wires from which end with two pin connectors from connector 6. One pin is intended for electrodes (the measuring pin is output to the pin, the auxiliary pin is to the body), the other is for the resistance thermometer. These plugs are mounted in tubular insulators.

The electrodes 3 and 4 are equipped with plastic caps 7, fixing the landing of the electrodes in the holder and allowing, if necessary, to perform emergency dismantling.

The holder 2 is screwed into the housing 1 by a thread, and the docking of these parts is sealed with a rubber ring 8. A thrust washer 9 is installed in the housing 1, which prevents accidental axial movements of the electrodes and the thermometer.

On the opposite side from the holder 2, a cable block 10 is connected to the housing 1, carrying two cables - one for connecting electrodes, the other for connecting a resistance thermometer, which end with sockets. The entry of the cable block and cables into the housing 1 is sealed with a rubber washer (included in the unit) and is fixed in the housing 1 with a union nut 11. The sensor is equipped with a flange 12 that is attached to the housing 1. By means of three set screws 13 resting against a groove on the housing.

To protect the protruding parts of the electrodes during installation, dismantling, storage and calibration using buffer solutions, a protective cup 14 with a screw plug 15 is placed on the groove of the holder 2. The latter is equipped with a rubber sealing ring 16 and has an internal bore with a side hole through which Distilled water or the corresponding buffer solutions are kept in the cavity between the electrodes. They keep the electrodes in operative condition between production cycles and allow Suitable to make the sensor calibration.

All metal parts of the sensor are made of stainless steel grade 12X18H9T, the cap and the glass are made of F-4 fluoroplastic, the caps and thrust washer are made of heat-resistant polyethylene. .. „: A general view of the device is shown in FIG. 2, and the block diagram of FIG. 3.

the device includes the following main nodes and blocks (Fig.Z):

electrode system for measuring pH 1 and temperature sensor 2

- remote input amplifier 4, matching the high-resistance output of the electrode system with the input stage of the high-resistance converter 5;

-switch 6, dividing in time the passage to the input of an analog-digital signal converter from the electrode system and the temperature sensor;

-analog-to-digital converter 7, which performs the conversion of the output signal of the switch into a digital code;

-programmable controller 9, which controls the operation of nodes and blocks and performs mathematical processing of information received from an analog-digital converter;

-matrix indicator 8, which displays the measurement result and performs the function of the interface between the device and the operator;

-Keyboard 10 for selecting and controlling device operating modes;

- power units 3 and 11.

The operation of the device is as follows. The signal from the output of the ion-selective electrode system 1 is fed to the first input of the remote amplifier 4. The signal from the output of the temperature sensor 2 is fed to the second input of the remote amplifier 4. The remote amplifier is designed to coordinate the output parameters of the electrode system and the temperature sensor with subsequent stages of the device. From the output of the remote amplifier, the signals are fed to the switch 6 for separation in time of their passage to the input of an analog-digital converter 7. Programmable controller 9 controls the operating modes and. the order in which signals are transmitted, calculates the values

parameters for the purpose, transmits the results of measurements and calculations of pH and temperature for visual control to a graphic liquid crystal indicator 8 and through the output signal generation circuit 12 to the upper level system (recorder, personal computer, etc.) - Power supplies 3 and 11 are designed to form voltages required for operation of the remote amplifier and secondary converter.

For example, a programmable controller provides automatic correction of the effect of temperature on the slope of the characteristics of the electrode system and on the change in the pH of the medium from temperature, the conversion of pH values into units of titratable acidity, etc.

Claims (1)

An industrial pH meter with a sterilizable sensor for food media, comprising an immersion sensor with a measuring glass electrode for determining pH and an auxiliary reference electrode installed in the sensor housing, as well as a high-resistance transmitter for measuring the emf of the glass and auxiliary electrodes, characterized in that the composition of the sensor additionally introduced a temperature sensor for measuring temperature, a measuring glass electrode is made with a solid electrolyte from an alloy with a carrier of hydrogen ions, and an auxiliary flax reference electrode is formed on the basis of non-flowing polymer electrolyte, wherein the electrodes and the temperature sensor is sealed in the sensor housing using silicone sealant and rubber gaskets, moreover, high-impedance converter further includes an integrated programmable controller, providing automatic actuation of values of the measured pH value to the temperature of 20 ^o C. and recalculating pH values to titratable acidity values.