Are infrared combustible gas detectors better than catalytic combustion types?

I consulted a company; the price wasn’t too high, and they said there was a 3-year warranty. I want to use it for a few months first

It works well for hydrocarbons, and its advantage is stability. But not all hydrocarbons can be measured; for example, styrene cannot. Check the manufacturer’s technical specifications for details. @jiaguoyun

1. In terms of price, infrared systems are definitely more expensive than catalytic combustion systems. 2. From the perspective of future maintenance, infrared systems require no maintenance, while the sensors in catalytic combustion systems need to be calibrated regularly. The sensor needs to be replaced. 3. When choosing an infrared sensor, it is important to note the difference between single-infrared and dual-infrared versions, as their prices vary. But the manufacturers will tell you that the functions are the same. There are still differences actually.

The combustible gas detector uses the latest generation of low-power, highly interference-resistant carrier catalytic sensors. It forms a detection bridge with two fixed resistors. When flammable gases present in the air diffuse to the surface of the detection sensor, they undergo rapid flameless combustion under the action of the catalyst on the sensor surface; the heat generated from this reaction increases the resistance value of the platinum wire in the sensor, resulting in a differential pressure signal being output by the detection bridge circuit. The magnitude of this voltage signal is directly proportional to the concentration of flammable gases. After amplification, it performs voltage-to-current conversion, and transforms the percentage concentration (%LEL) of flammable gases within the lower explosion limit into a 4-20mA standard signal for output. An infrared principle sensor is a sensor that utilizes the physical properties of infrared light for measurement; it consists of an optical system, a detection element, and a photodetection element. Optical systems can be divided into two categories based on their structure: transmissive and reflective. Based on their working principle, detection elements can be divided into thermosensitive detection elements and photoelectric detection elements; among thermosensitive elements, thermistors are the most widely used. When a popular resistor is exposed to infrared radiation, its temperature rises, causing a change in its resistance; this change is then converted into an electrical signal through a conversion circuit and transmitted as an output.

It was explained in a professional manner, with clear distinctions between catalytic combustion and infrared technology; thanks for sharing

Of course, infrared is the better choice; the price will also be much higher. The quality will definitely be good as well. It can last 5 years if the environment is good.

Learned: handshake

Infrared gas detectors have a relatively limited range of application; they are generally used to detect CO2 as well as certain hydrocarbons, and their performance is quite stable. Theoretically, catalytic combustion type detectors can measure all combustible gases (volatile liquids), making them suitable for a wide range of applications. However, when using this type of gas detector, the following points should be taken into consideration: 1. Catalyst poisoning, and 2. Proper ventilation is necessary during installation; detectors cannot measure pure combustible gases with very low O2 concentrations. 3. When manufacturers calibrate catalytic combustion detectors, they generally use CH4 for calibration; however, the heat of combustion of different gases can vary significantly, necessitating the use of calibration coefficient conversions. Compared to toxic gases, the measurement range for combustible gases in ppm is relatively broad; VOL% (Lower Explosive Limit, LEL%) is expressed as a percentage. The truly expensive probes are those for time-of-flight ion detection; their price is roughly 5 times that of catalytic combustion probes, or even more. Also, although catalytic combustion types are now widely used, the probes are still generally imported from abroad, as domestic probes are quite unstable.