A method of exempting from factory calibration of gas detectors

Abstract

The invention relates to a calibration-free method for a gas detector, which includes the following steps in turn: S100, place the gas detector in clean air for a period of time T, take multiple samples, and determine the zero-point AD sampling value; S200, pass the minimum two Multiplication fits the curve equation of the built-in characteristic curve of the sensor in the gas detector; S300 implants the curve equation of the built-in characteristic curve of the sensor fitted in S200 into the gas detector through the host computer software and RS485 interface; S400, carry out ventilation verification on the gas detector to confirm the validity of the characteristic curve equation; using the method of this technical solution, the sensor characteristics of a certain gas can be built into the gas detector. Before the gas detector leaves the factory, only need to carry out Simple ventilation verification, coefficient adjustment, and correction of individual differences can complete the factory preparation, avoiding the current complicated and cumbersome operations, and greatly improving production efficiency.

Description

technical field [0001] The invention relates to the technical field of gas detectors, in particular to a method for ex-factory calibration of gas detectors. Background technique [0002] Before the gas detector leaves the factory, it is often necessary to perform zero calibration and calibration of the detector according to the type of sensor, the type of gas detected, and the differences between the individual components of the detector. The purpose is to ensure the detection accuracy of the detector and reduce the measurement error. [0003] At present, the customary method for zero point calibration and calibration of gas detectors is as follows: the first step is to pass standard gases of different concentrations into the gas detector, and establish the corresponding relationship between gas concentration and sensor output sampling. The basic algorithm of calibration is once Linear function y=kx+b, as attached figure 1 As shown; in the second step, on the basis of the c...

AI Technical Summary

Problems solved by technology

[0004]The above calibration method needs to go through a lot of ventilation measurement tests. For a gas detector for a certain gas detection, the zero point calibration needs to measure 9-10 points repeatedly. If If the detection temperature range is between -40-70°C, then the above calibration process needs to be repeated for each sensor, each gas concentration, and each temperature range. For example, when the concentration is 20% LEL, it is necessary to repeat 8 times. The workload is very heavy to explore the data of the temperature segment and 10 humidity segments; and when the sensor used is a nonlinear sensor, segmental calibration is often required. When the linearity of the sensor used is poor, segmental calibration is required. The work is very complicated, the calibration results are generally not ideal, and it is time-consuming and labor-intensive, seriously affecting production efficiency

Images