RU2012134123A - METHOD FOR CALIBRATING SEMICONDUCTOR GAS SENSORS AND DEVICE FOR ITS IMPLEMENTATION - Google Patents

Abstract

1. The method of calibration of semiconductor gas sensors, which consists in the fact that to determine the concentration of the gas component, in particular hydrogen and calibrate the sensor in the presence of gaseous impurities, measure the electrical signal at the output of the semiconductor sensor with a sensitive layer of metal oxide when it is heated to a given temperature, from the value of this signal, the conductivity of the sensitive layer of the semiconductor sensor is determined, stored, compared with the previously obtained calibration The hydrogen concentration is determined by this value, characterized in that the semiconductor sensor is calibrated using a hardware-software complex using the software package SEMSENSOR and MATLABSEM, written in the assembler programming language, implemented on a PC in the integrated operating environments Silicon Laboratories IDE and MATLAB 7.01, such so that a cyclically predetermined number of times (K times) is heated the sensitive element of the semiconductor sensor in clean air (PGS-1) to a temperature of T1 and cooled to a temperature of T2, then in t the next K cycles of heating and cooling feed the calibration gas mixture PGS-2 to the area of the sensor, then for the next K cycles feed the calibration gas mixture PGS-3 to the region of the sensor, then for the next K cycles feed the calibration gas mixture PGS-N into the region of the sensitive element, build a family of N = 4 time dependences of the conductivity of the gas-sensitive layer σ (t) for each gas mixture and for a fixed time ti in the cycle, determine the calibration characteristic,

Claims (5)

1. The method of calibration of semiconductor gas sensors, which consists in the fact that to determine the concentration of the gas component, in particular hydrogen and calibrate the sensor in the presence of gaseous impurities, measure the electrical signal at the output of the semiconductor sensor with a sensitive layer of metal oxide when it is heated to a given temperature, from the value of this signal, the conductivity of the sensitive layer of the semiconductor sensor is determined, stored, compared with the previously obtained calibration The hydrogen concentration is determined by this value, characterized in that the semiconductor sensor is calibrated using a hardware-software complex using the software package SEMSENSOR and MATLABSEM, written in the assembler programming language, implemented on a PC in the integrated operating environments Silicon Laboratories IDE and MATLAB 7.01, such so that a cyclically predetermined number of times (K times) is heated the sensitive element of the semiconductor sensor in clean air (PGS-1) to a temperature of T1 and cooled to a temperature of T2, then in t the next K cycles of heating and cooling feed the calibration gas mixture PGS-2 to the area of the sensor, then for the next K cycles feed the calibration gas mixture PGS-3 to the region of the sensor, then for the next K cycles feed the calibration gas mixture PGS-N into the region of the sensitive element, build a family of N = 4 time dependences of the conductivity of the gas-sensitive layer σ (t) for each gas mixture and for a fixed time ti in the cycle, determine the calibration characteristic, Rouge in intelligent processor semiconductor sensor 5 - $${\sigma }_i^k,ti,T\mathrm{one}i,T2i,\Delta {12}^i=F\left(C{i}^k\right),\left(\text{one}\right)$$

where k = 1, 2, 3, ..., N; i = 1-CH4, i = 2-C3H8, i = 3-H2, i = 4CO, i = 5-NH3; ti is the moment of time measured from the start of heating of the sensor at which N measurements of the conductivity take place in the 6, 12, 18, ... 6 · N cycle of heating and cooling; T1i is the heating temperature of the HS sensitive element in the ith gas environment, T2i is the heating temperature of the HS in the ith gas environment, Δ12 ⁱ is the cooling time of the HS from T1 to T2; Ci ^k is the concentration of the ith gas component in the PGS-k calibration gas mixture supplied to the sensor. 2. The method for calibrating semiconductor gas sensors according to claim 1, characterized in that the calibration algorithm contains the initial (before calibration) testing of the operability of the smart module and the initial setting of the initial parameters of the heating mode and recording the identification data of the semiconductor sensor. 3. The method for calibrating semiconductor gas sensors according to claim 1, characterized in that there is an OscilloGRAPH calibration mode, which consists in an exponential law of increasing or decreasing the concentration of the gas component in the region of the sensing element, in which a family of up to 16 time can be built in one window realization of σ (t) with a heating and cooling cycle from 5 s to 20 s. 4. The method for calibrating semiconductor gas sensors according to claim 1, characterized in that the family of temporary implementations of σ (t) in the CALIBRATION mode and calibration characteristics, any cycle in a single heating mode, in a cyclic mode of training and stabilization of the sensor sensitivity, graphs of bias voltage of operational amplifiers the electronic unit for normalizing the output electrical signal of the conductivity of the gas-sensitive layer can be recorded and archived into the database in both graphical form and a text file. 5. The method for calibrating semiconductor gas sensors according to claim 1, characterized in that there is a graphical menu that allows you to carry out the operations of transferring curves superimposed on other graphs, insert explanatory texts anywhere in the graph, smooth the piecewise-approximated curve, determine the equation of the curve close to the smoothed calibration characteristic (1).