18 5 月, 2024

Manufacturing

Processing Machinery

What is a gas detector and how to select and use it?

7 min read

Gas detector is a kind of equipment equipped with a highly sensitive sensor, can keenly feel the prevalence of a small amount of harmful gases in the air, combustible gases, etc., is a class of equipment that needs to be assembled in various fields of industrial production. High-quality combustible gas detector in the current market has a very large scale of use. So, what is a gas detector and what is the market potential?

1, the gas detection equipment market has great potential

Gas detector is a kind of instrumentation tool for gas leak concentration detection, which includes: portable gas detector, handheld gas detector, fixed gas detector, online gas detector, etc. The main use of gas sensors to detect the type of gas present in the environment, gas sensors are used to detect the composition and content of the gas sensor. Gas sensors are a large category of chemical sensors. From the working principle, characterization to measurement technology, from the materials used to the manufacturing process, from the detection object to the application field, can constitute an independent classification criteria, derived from a variety of classification system, especially in the issue of classification standards have not been unified, to its strict and systematic classification is quite difficult.

The gas detector can achieve high-precision measurement, LCD display, high-decibel alarm, simultaneous detection of multiple gases, real-time monitoring, data storage and other functions, with a wide range of measurement, powerful role, flexible operation, long service life, high measurement accuracy, etc., and has been widely used in petroleum, chemical, storage, fire, environmental protection, metallurgy, gas transmission, biological medicine, energy and electricity, etc. The market demand space is relatively broad.

Grand View Research, Inc has published a report, the report points out that by 2028, the global gas detection equipment market size is expected to reach $ 8.38 billion, the industry is expected to grow at a CAGR of 9.7% from 2021 to 2028, the gas detection industry will enter the fast lane of development, the market holds unlimited potential. LCD Display for gas detectors.

2, how to choose a gas detector

So when using, we should pick from those aspects of the gas detector?

The first is stability, which is the stability of the basic response of the sensor throughout the operating time and depends on zero-point drift and interval drift. Zero point drift is the change in the sensor output response throughout the operating time in the absence of the target gas. Interval drift is the change in the output response of a sensor continuously placed in a target gas and is expressed as a reduction in the sensor output signal over the operating time. Ideally, a sensor would have a zero-point drift of less than 10% per year under continuous operating conditions.

Next is sensitivity, which is the ratio of the change in sensor output to the change in the measured input and is largely dependent on the technology used in the sensor construction. Most gas sensors are designed using biochemical, electrochemical, physical and optical principles. The first consideration is to choose a sensitive technology which is sufficiently sensitive to detect the percentage of valve limit or minimum explosion limit of the target gas.

The third is selectivity: this can be determined by measuring the sensor response produced by a certain concentration of the interfering gas. This response is equivalent to the sensor response produced by a certain concentration of the target gas. This characteristic is important in applications where multiple gases are tracked because cross-sensitivity reduces the repeatability and reliability of the measurement, and the ideal sensor should have high sensitivity and high selectivity.

The fourth explosion-proof: gas detectors with explosion-proof features can resist the impact of the explosion and heat without damage. In coal mines, steel, smelting, petrochemicals, pharmaceuticals and other chemical sites, has been the gathering point of toxic and hazardous gases and flammable and explosive gases, in the choice of gas detectors must choose gas detectors with explosion-proof function.

3, how to use the gas detector?

1、Before using

① Read carefully the instruction manual corresponding to the gas detector before operation, and familiarize yourself with the machine’s performance and operation methods.

② Check whether the battery power is sufficient, if found that the battery power is insufficient should be replaced in a timely manner.

③ Check the air inlet air filter for debris blockage, blockage needs to be cleaned up or replaced.

④ self-test during the power-on process should listen to the grading alarm sound and light alarm, vibration alarm is accurate, if not set to meet the requirements are not allowed to use, and should be immediately calibrated.

⑤ start when long press the start button to hold for three seconds, enter the self-test state, observe the detector set low alarm value, high alarm value is set accurately (CO detector level alarm 50ppm, the second alarm 100ppm; oxygen detector level alarm 19.5%, the second alarm 22%; hydrogen sulfide detector level alarm 10 ppm, the second alarm 15ppm), if not meet the requirements Setting is not allowed to use, and should be immediately calibrated. Self-test during start-up should listen to the graded alarm sound and light alarm, vibration alarm is accurate, such as does not meet the requirements set not allowed to use, and should be immediately calibrated.

⑥ Observe whether the initial value is accurate after switching on under fresh air conditions (CO detector initial display 0 ppm; O2 detector initial display 20.9%; hydrogen sulfide detector initial display 0 ppm), if the displayed value is inaccurate strictly prohibited to use, should be immediately calibrated.

2、In the process of use

① Portable gas detector should be worn as close as possible to the mouth, nose parts, such as the front lapel of the clothes, jacket pockets, etc. It is strictly prohibited to place the alarm in the pocket and other parts that are not easy to view, affecting the detection value.

② Collision should be avoided as much as possible during use, causing abnormal detection data.

③ gas detector sensor and other components belong to the precision parts, adjust the instrument do not casually open the cover, the use of the process should pay attention to waterproof and impurities into, to prevent the data caused by abnormalities.

④ When using, if the indicator light flashes continuously, the display suddenly does not show the value, the gas obviously exceeds the regional display value does not move, the gap is large and other abnormal conditions should immediately stop work, evacuate to the fresh air area to observe what is the problem, and promptly eliminate, otherwise it is strictly prohibited to continue to use.

⑤ Operation in case of exceeding the standard of various types of gas detection to implement national and company regulations:

Gas site operations (excluding confined spaces) concentration and operating time requirements:

When the concentration of CO in the air is 24ppm, it can work normally; when the concentration of CO in the air is 40ppm, it can work for 1 hour; when the concentration of CO in the air is 80ppm, it can work for half an hour; when the concentration of CO in the air is 160ppm, it is only allowed to work for 15~20 minutes, and the interval between each work is 2 hours.

Oxygen work: the oxygen content of the operating area shall not be less than 19.5%, and the oxygen content in the limited space is generally 19.5% to 21%, and shall not be greater than 23.5% in the oxygen-rich environment.

Hydrogen sulfide operations:

When the concentration of hydrogen sulfide is less than 40ppm, you can wear a filtered gas mask and indicate the applicable substance on the surface of the canister.

When the concentration of hydrogen sulfide is greater than 40ppm or unknown concentration or sulfur dioxide concentration is higher than 2ppm in the area of operation should use positive pressure air respirator.

It is strictly forbidden for anyone to enter an area that may contain hydrogen sulfide gas without wearing appropriate protective equipment, and it is forbidden to remove anti-gas gear in toxic areas.

(6) If dizziness, ringing in the ears, blurred vision, nausea and other conditions occur in the operation should immediately stop work, evacuate to the fresh air area (pay attention to the direction of air flow, choose the windward entrance), such as the state of affairs should immediately start the emergency response, carry out self-help, other rescue.

3、After use

① Portable gas detector press and hold the shutdown button after use, the display shows 5 seconds countdown, the LCD shows “off” after the countdown, then the instrument does not show, the instrument shutdown, it is strictly prohibited to directly deduct the battery forced shutdown.

②The dust attached to the surface should be cleaned after the instrument is turned off, and the equipment should be cleaned well.

③ When the instrument is not working for a long time, it should be turned off and placed in a dry, dust-free environment that meets the storage temperature.

④ gas detector to implement a system of special management, to prevent the loss of such cases caused by the lack of equipment, affecting the normal use.

4, the level of localization

The current layout of the gas leak detector market of international companies including Figaro, Honeywell, Huarui, MSA, etc.; domestic enterprises mainly include Hanwei Technology, An Trustworthy Electronics, Changqing Computer, Chi Cheng Electric, Inguison Security, Xinhaos Electronics, Zehong Technology, but the Thai security, etc.. China’s gas leak detector industry started late, for a long time, the core technology has been monopolized by foreign enterprises in developed countries, the domestic market demand is seriously dependent on imports.

However, in recent years, in the context of the accelerated rise of local enterprises, the domestic gas leak detector market competitiveness is increasing, which in turn has led to an accelerated increase in the level of localization in the domestic market. At present, the domestic gas leak detector low-end market has basically achieved localization, while the high-end market localization is still at a low level, the future of local enterprises still need to continuously upgrade technology and increase product innovation, the industry has huge room for growth.

What is a gas detector and how to select and use it?