What characteristics should be noted when selecting a gas detector?
Gas detectors are classified based on the detection target, which means that any instrument used to detect gas composition and concentration is a gas detector. Whether it is using physical or chemical methods, any instrument used to detect gas concentration in the environment is called a gas detector. However, many consumers are not familiar with gas detectors and do not know how to choose them. Therefore, there are 7 characteristics to pay attention to when choosing a gas detector:
1. Reliability
The longer the lifespan of the sensor, the better. Generally speaking, the lifespan of the sensor is at least 2 years, while that of combustible gas sensors is 2-5 years. The longer the average time to error, the better. What is the accuracy and precision? The smaller the error value, the better. The product warranty period is generally 2 years.
2. Applicability
The identification and evaluation of hazardous gases on the site of confined space operations should be carried out by enterprise professionals and experienced work supervisors or employees on site, in order to determine whether the sensors of the selected detector meet the usage requirements.
3. Stability
What are the values of zero offset and full amplitude offset? The smaller the value, the better.
What is the impact of interfering gases? All sensors, except for oxygen, will react with other gases in varying degrees. Electrochemical sensors that detect hydrogen sulfide often occur, so users must be as familiar as possible with gases that may exist in limited spaces. For direct reading instruments, interference from interfering substances is a difficult problem to overcome. Therefore, in any case, if the interference situation of direct reading instruments has not been evaluated, it is not recommended to use direct reading instruments, and it is not advisable to replace sampling analysis methods with direct reading instruments.
4. Convenience
Lightweight, small in size, easy to wear and comfortable to maintain.
5. Correction requirements
Calibration method, duration, and ease of use. There are two calibration methods - laboratory and on-site calibration. On site calibration involves exhaling the oxygen sensor, and the oxygen reading of the instrument must decrease and an alarm occurs.
6. Legibility
Numerical or pointer type gas detectors. Generally speaking, numerical values have the advantages of being easy to read and reducing false positives. Is the display area large enough, with background lighting and larger fonts for easy reading and understanding.
Is the alarm loud enough to distinguish it from background noise. Generally, it is applicable with an efficiency of over 90dB (A). Can the alarm flashing light be identified from various angles. Can the signal be continuously displayed as the measured gas concentration changes, and the alarm can only be stopped after confirmation or countermeasures are taken.
7. Protection requirements
Is the explosion-proof safety level applicable to the workplace, is intrinsic safety certified, has explosion-proof certification, or only has intrinsic safety design. Anti electromagnetic wave level. Because electromagnetic waves generate induced currents that cause errors or instability in instrument readings, the sources of electromagnetic waves are generally electronic products such as walkie talkies, radio broadcasts, and mobile phones that emit electromagnetic waves.
