Common Sense for Choosing Gas Detectors
Gas detector is an instrument tool for detecting gas leakage concentration, mainly referring to portable/handheld gas detectors. Mainly using gas sensors to detect the types of gases present in the environment, gas sensors are sensors used to detect the composition and content of gases. It is generally believed that the definition of gas sensors is based on the classification of detection targets, which means that any sensor used to detect gas composition and concentration is called a gas sensor, regardless of whether it is using physical or chemical methods. For example, sensors that detect gas flow are not considered gas sensors, but thermal conductivity gas analyzers are important gas sensors, although they sometimes use generally consistent detection principles.
Precautions for purchasing gas detectors: Have you paid attention to the selection of gas detectors? How to choose based on the environment? How to choose based on space? How to select based on gas? Regardless of the reason we choose, we need to pay attention to the following points:
1. Reliability
The longer the lifespan of gas detectors, the better. Generally speaking, the lifespan of sensors is generally 2-3 years, while that of combustible gas sensors is 3 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 1 year.
2. 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 needs to decrease and an alarm occurs.
3. Stability
What are the zero offset and full amplitude offset values of the detector? The smaller the value, the better.
4. 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.
5. Convenience
Lightweight, small in size, easy to wear and comfortable to maintain.
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. Based on the measurement object and measurement environment
Determine the type of sensor based on the measurement object and measurement environment. To carry out a specific measurement work, the first thing to consider is which principle of sensor to use, which requires analyzing various factors before determining.
8. Response characteristics (reaction time)
The frequency response characteristics of sensors determine the frequency range to be measured, and it is necessary to maintain undistorted measurement conditions within the allowable frequency range. In fact, the response of sensors always has a certain delay, and it is hoped that the shorter the delay time, the better.
9. Linear range
The linear range of a sensor refers to the range where the output is proportional to the input. In theory, within this range, the sensitivity remains constant. The wider the linear range of the sensor, the larger its range and can ensure a certain measurement accuracy.
