How to Calibrate Gas Detector?
Gas detector is a kind of gas leakage concentration detection instrument tool. ATO sells portable gas detector that continuously and rapidly monitors specific concentrations of gases in the surrounding environment or confined spaces. Gas sensors are mainly used to detect the types of gas in the environment. Gas sensors are used to detect the composition and content of gas.
But it in use after a period of time due to multiple sensor detection, there may be misoperation and other reasons, may lead to increased errors in the gas detector, measurement data is not accurate. Therefore, it is recommended that the gas detector be calibrated after a period of use in order to detect the correct results. In this article, we will introduce the calibration of gas detectors provided by ATO automation.
As shown in the figure. Before calibration, the cylinder pressure relief valve needs to be connected.
Gas detector mainly contains 2 calibrations: one is zero calibration, the other is span calibration.
Zero Calibration:
Zero calibration must be made in clean air. Press "menu" to enter the parameter setting mode, select "zero calibration" and press button to enter this mode. Please observe the value of real-time "concentration", until the real-time concentration value is stable, if the value is not zero or drift is large, the zero calibration can be made. Press the button, the real-time concentration will be reset to zero. When press "ESC" to return to the detection interface, the gas concentration value will display 0.
Note: Oxygen detector, nitrogen detector and CO gas detector (gas present in the air) cannot do zero point calibration in air, only target point calibration (the target point concentration is the standard concentration value in clean air).
Span Calibration:
The span calibration must be made with standard gas. In the detection interference, press "menu" to enter the parameter setting mode, select "span calibration". Press the button to enter the password input interface, as shown in Figure 1, press "menu", the cursor will select the password characters from left to right.
After entering the password accurately, press the button to enter the span calibration interface as shown in Figure 2, and the interface will display "real-time concentration" and "set value".
The "real-time concentration" is the data calculated by several internal calibration parameters. The calibration process is to recalculate the internal parameters of the detector. The "set value" is a parameter that requires manual input, and the input value is the standard gas concentration value.
The calibration process is as follows:
- Connect the CH4 gas detector with standard gas cylinder by hose. (shown in Figure 3)
- Enter the span calibration interface by password, set the “SET value” as the standard gas concentration.
- Release the standard gas to the detector in a flow rate of 500 mL/min. The value of "real-time concentration" will become larger gradually, and become stable after 30 seconds.
- When the value of "real-time concentration" is stable, press the button, the value of "real-time concentration" will be same with or almost same with the "set value". The calibration is finished.
- Cut off the standard gas supply. Press "ESC" to go back to detection interface.
