What is a pid monitor pid gas detector

What is a pid monitor?

PID monitor is also called PID gas detector, which is photoionization gas detector. The detection principle is photoion technology. It is a simple, easy-to-use and convenient monitor. It is a photoionization (PID) detector that can detect 30 Various volatile organic compounds (VOCS), including benzene, toluene, and xylene. With fast response and high sensitivity, photoionization is an effective method for detecting volatile organic compounds (VOCS). The main core is an instrument that relies on a built-in PID sensor to react and analyze gas concentration based on an ultraviolet (UV) light source principle.

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Working principle:

PID uses an ultraviolet lamp (UV) light source to break organic matter into positive and negative ions (ionization) that can be detected by the detector. First, the electrons generated by ionization and the positively charged ions form weak ions under the action of the electric field. Current, then the PID gas detector reflects the content of the substance by detecting the current intensity. Finally, the detector measures the charge of the ionized gas and converts it into a current signal. The current is amplified and converted through the corresponding algorithm, so that The concentration components of the outgoing gas.

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Advantages and features

1.PID gas detectors have a wide range of applicable detection ranges. Currently, they can basically be used to detect VOC volatile organic compounds, and can also be used for emergency trace gas leak detection. (Note: Due to the limited life of the PID lamp and its susceptibility to humidity, it is not recommended for gas online monitoring system applications)

2.The PID gas detector has high accuracy and can detect VOC volatile organic gases at the ppb level (one part per billion). In addition, the traditional PID photoionization gas detector can detect ppm level (one part per million). For organic gases, the accuracy exceeds other principles such as infrared, electrochemistry, and catalytic combustion.

3.The PID gas detector is non-destructive to the detected gas and has good stability. Generally, the gas detector ionizes the gas after inhaling it, and the ions formed by the gas molecules form the original gas molecules after discharge, which is harmful to the original gas. No molecular damage.

4.The PID gas detector has fast response speed and long life. Under normal working conditions, the PID gas detector can respond almost in real time and can test continuously. In addition, the service life of a UV lamp is usually thousands of hours, and the design service life of conventional PID gas detectors is as high as more than 5 years.

Disadvantages: PID gas detectors are relatively expensive. If you have a limited budget, it is recommended to consider other traditional electrochemical gas sensors, infrared gas sensors, and semiconductor gas sensors as the core gas detectors.

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What gases are suitable for PID gas detectors to measure?

The PID gas detector is suitable for detecting VOC, TVOC, benzene, toluene, ammonia, carbon disulfide, trimethylamine, olefins, aromatic hydrocarbons, acetone, acrylonitrile, acetic acid, ethyl acetate, ether, methyl mercaptan, methyl sulfide, styrene, Volatile gases such as vinyl chloride, but the range of VOC can be said to be quite complex, with even millions of types, so the detection range must be verified before using the PID gas detector.

Note: Not all gases can be detected by the PID gas detector. This is mainly related to the ionization potential of the ultraviolet light lamp in the PID sensor. That is, gases higher than the ionization potential cannot be ionized and separated. For example, the gases that cannot be detected include: nitrogen, oxygen, carbon dioxide, carbon monoxide, sulfur dioxide, ozone, methane, ethane, propane, Freon, etc. In addition, PID gas detectors are not suitable for detecting radioactive gases, highly toxic gases, and flammable gases (most of them do not react to LEL flammable gases).

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By using the above technology, the structure of the NDIR co2 sensor will be greatly simplified compared to previous instruments, the power consumption of the instrument will also be greatly reduced, and the cost of the sensor will be less than 1/4 of previous technologies. At the same time, this type of sensor can be modularized and standardized, can achieve high output in a short time, is suitable for large-scale mass production, and can be widely used.