How Infrared Sensors Differ from Catalytic Combustion Sensors

Infrared sensor

Sensors play a key role in monitoring flammable gases and flammable vapors, including catalytic sensors and infrared (IR) sensors. Environment, response time, and temperature range are just factors to consider when deciding which technology is best to use.

So, what are the differences between catalytic sensors and infrared (IR) sensors? Why do both technologies have advantages and disadvantages, And how to differentiate which method is best for different environments?

Infrared sensor technology is based on the principle that certain wavelengths of infrared (IR) light will be absorbed by the target gas. Usually there are two emitters inside the sensor that generate infrared beams: a measurement beam with a wavelength that will be absorbed by the target gas and a reference beam that will not be absorbed. Each beam has the same intensity and is deflected onto a light receiver by a mirror inside the sensor. The difference in intensity between the reference beam and the measurement beam will be used to measure the concentration of the gas present.

In many cases, infrared (IR) sensor technology offers many advantages over catalytic combustion technology, or is more reliable in specific environments like low oxygen and inert environments that can reduce catalytic combustion sensor performance. It's just that the infrared beam interacts with the surrounding gas molecules, giving the sensor the advantage of not facing the threat of poisoning or suppression. Infrared technology provides fail-safe testing. This means that if the infrared beam fails, the user is notified of this failure.

Ideal for the oil and gas industry, infrared sensors can detect methane, pentane, or propane in explosive, low-oxygen environments where catalytic combustion sensors is not the first choice.

However, IR sensors are not perfect because they can only output target gas linearly. If infrared sensors respond to other flaw gas, the target gas will be non -linear. Just like catalytic combustion sensors are prone to poisoning, IR sensors are also vulnerable to severe mechanical and high -temperature shocks, and they are also strongly affected by stress changes.

In addition, infrared sensors cannot be used to detect hydrogen, we recommend using catalytic combustion or semiconductor sensors in this case. The primary goal of security is to choose the right testing technology to minimize the harm of workplace. We hope to clearly identify the differences between these two sensors, which can improve people's awareness of how to maintain safety in various industries and dangerous environments.

Catalytic sensor

Catalytic sensor is a device that is used to detect a combustible gas or flammable steam that enters the explosion range to warn the level of gas concentration rising.

The working principle of the sensor is a circle of platinum silk, which is equipped with a catalyst inside, forming a small active bead, which can reduce the gas ignited temperature that around it. When there is flammable ga. The temperature and resistance of active bead will increase relative to the resistance of inert reference bead. Measure the difference in resistance, so as can measure the existence of gas concentration. Because there have catalyst and bead, the catalytic sensor is also called catalytic combustion or catalytic bead sensor.

Catalytic sensor was originally founded by British scientists and inventors Alan Baker in the 1960s, and catalytic sensors were originally designed for long -term use of flame safety lights and Canari technology. Today, the device is used in industrial and underground applications, such as mines, tunnels, oil refineries and petroleum rigs.

Compared with IR sensors, due to the differences in technical level, the cost of catalytic sensors is relatively low, but they may need to replace them more frequently. In the case of linear output corresponds to the gas concentration, can use correction factor to calculate the approximation of catalytic catalytic to other flammable gas. When there are a variety of flammable gas, the catalysis can be a good choice.

The fixed detection of the built -in catalytic sensor outputs the MV bridge signal of the probe, which is very suitable for installation in the difficulty of reaching; it can be debugged and calibrated by the controller panel. On the other hand, because the catalytic combustion work requires oxygen in the process of work, so catalytic combustion is difficult to use in an environment with low oxygen concentration. For this reason, a closed space instrument containing a catalytic gas alarm usually requires a detector used to measure oxygen. In the environment where compounds contain silicon, lead, sulfur and phosphate, sensors are prone to poisoning (irreversible sensitivity decreases) or being suppressed (reduced sensitivity), which may cause harm to people in the workplace. If it is exposed to high concentration gas, it may damage the catalytic sensor. In this case, catalytic combustion will not do"fail protect", which means that if the gas is detected, no notification will be issued when the instrument fails. Any failure can only be determined by the BUUP test before each use to ensure that the performance will not decrease.

Comparison of infrared sensor and catalytic sensor