RU2221240C2 - Method ensuring serviceability of gas analyzer - Google Patents

Abstract

FIELD: measurement technology, equipment testing serviceability of gas analyzers operating at increased positive and low negative environmental temperatures. SUBSTANCE: thermoelectric Peltier's module is anchored on electrochemical cell. Temperature- sensitive elements are positioned on electrochemical cell and in path of air flow. Temperatures of electrochemical cell and gas are measured and temperature difference processed by information processor, controller and amplifier generates controlling action proportional to direction and current through Peltier's module which is sent to thermoelectric Peltier's module. The latter heats or cools electrochemical cell depending of direction of current. Technical result of invention lies in ensured serviceability of gas analyzer at low temperatures up to -50 C and high temperatures up to +60 C. EFFECT: ensured serviceability of gas analyzer.

Description

The invention relates to measuring equipment - methods and devices of gas analyzers. It can be used to quantify the content of gases in ambient air at low and high temperatures.
Known analyzer of the French company "ANALYSE DETECTION SECURITE". Depending on the modification, it contains a specific gas sensor, a flow inducer, a throttle for restricting the gas flow, a device for processing information from a gas sensor, a device for displaying information on a digital display, sound and light alarms for gas content. The following modifications are possible - GAS LINK, GAS MONITOR, GAS MASTER, DETECTIVE, GAS MAN, POLYTOX 2000.

The disadvantage is the operating temperature in the range from -10 to +50 ^o C [1].

 The method includes the operation of suctioning an air mixture with an admixture of gas, pumping through a sensor (sensor) that responds to a specific gas, regulating the flow of the air mixture through a sensor (sensc) to ensure metrology, supplying input voltage to the sensor (sensor), and removing output information from the sensor ( sensor) gas, processing of this information for digital indication, light and sound signaling.

 An analyzer of the Japanese company "RUKEN KENKU" [2] of the EC-565 type of various models is also known, containing a flow inducer, an inductor, an electrochemical element for detectable gas, an information processing unit, an analog-to-digital converter, a digital indicator, a signal lamp and an audible buzzer.

The disadvantage is also the limited range of ambient temperature (from 0 to +40 ^o C) and relative humidity (30-90%), the dependence on the presence of gaseous chlorine in the environment.

 Also known are the models of this company SC-90, FP-250, model 91.

The disadvantage is the same, the operating temperature is from +5 to +35 ^o C and from -10 to +40 ^o C. The method of determination is photometric detection with a paper detecting tape "FP-250", or the use of an electrochemical cell (sensor) using a microprocessor , liquid crystal indication on the display, audible and flashing LED alarms, the sample is taken by an internal diaphragm pump (inducer of gas flow through the sensor).

Also known is a portable gas analyzer of explosive gases and vapors - ACV-1, manufactured by the State Unitary Enterprise All-Russian Research Institute of Metrology named after D.I. Mendeleev [3], which also has a drawback - the range of operating temperatures is larger, but insufficient, from -35 to +50 ^o C.

The objective of the present invention is to expand the temperature range of operating temperatures in the region of its low values to -50 ^o C.

 As a prototype, we take the method used in the gas analyzer EC-565 [2].

The present invention is a method of ensuring the health of the gas analyzer in the field of low ambient temperatures up to -50 ^o C and high temperatures up to +60 ^o C.

This method uses the Peltier effect [4], the generation and absorption of heat during the passage of electric current of various sizes through the contact of two different semiconductors, while the heat generation is replaced by absorption when the current direction changes. The amount of heat generated or absorption is proportional to the magnitude and direction of the current passing through the layer
K _P = -T • Δα
where K _P - Peltier coefficient,
T is the absolute temperature, ^o K,
Δα is the difference in thermoelectric coefficients of Peltier conductors, the effect is greatest for semiconductors.

 To implement this method, a Peltier element module is mounted on the gas sensor (sensor), in which they use the property of their heat-absorbing surface to cool the body of the sensor (sensor) when a current flows of a certain magnitude and a certain direction through the Peltier element. To ensure coordination of the characteristics of the required current, an amplifier is used, which is controlled through the controller. A temperature sensor for the inlet gas stream is installed in the path of the gas gas flow, a temperature sensor for the sensor is mounted on the body of the gas sensor (s), and temperature sensors are installed for forced cooling or heating.

 According to the results of measuring the temperature of the sensor of the inlet gas flow, the temperature of the actual design of the gas sensor (sensor), determine the temperature difference, according to which the information processing device generates a control action in accordance with the Peltier effect proportional to the direction of the current and the current through the Peltier element, which form controller and amplifier, depending on whether you need to heat or cool.

 The proposed method meets the conditions of patentability, as it is new, the operations of monitoring the temperature of the incoming gas stream, the temperature of the sensor structure itself, the operation of additional heating or cooling of the gas sensor structure using the Peltier semiconductor module are added, the operation of innervation processing from temperature sensors and its conversion are added and control through the controller and amplifier on the Peltier element.

The proposed method has an inventive step, as it allows the possibility of the gas analyzer to operate at low temperatures up to -50 ^o C and high temperatures up to +60 ^o C.

 The proposed method is industrially applicable, since it provides the possibility of analyzing gases in the environment at a wider temperature range, which is especially important for metallurgy, gallurgy, and construction.

Sources of information
1. Catalog of the French company "ADS". Exhibition "Metallurgy". M., 1996.

 2. Catalog of the Japanese company "RUKEN KEUKU", 1995

 3. Advertising sheet for portable gas analyzer ACB-1, International exhibition "Etalon-2001", All-Russian Exhibition Center, August 21-24, 2001

 4. TSB, 3rd ed., Vol. 19. M .: Soviet Encyclopedia, 1975

Claims (1)

A method of ensuring the operability of a gas analyzer with an electrochemical sensor at low and high temperatures, characterized in that the Peltier thermoelectric module is mounted on the electrochemical sensor, placed on the electrochemical sensor and in the air flow path of the gas temperature sensors, measure the temperature of the electrochemical sensor and gas and the temperature difference using the device information processing, controller and amplifier generate a control effect on the Peltier thermocouple, proportional th direction and strength of the current through the Peltier thermoelement, which depending on the direction of current heats or cools the electrochemical sensor.