VOCs are measured in the air-Q by means of a resistive sensor as standard. Molecules "docking" on the surface of the sensor cause a change in the electrical resistance in the sensor. The measuring principle is proven and very well suited for most requirements. For special applications it is possible to use an additional PID sensor in the air-Q, which can be used in a free additional sensor slot in the measuring device. We introduce the air-Q VOC PID sensor and answer important questions about how it works.
How does a VOC PID sensor measure?
VOC PID sensors (Volatile Organic Compounds - Photoionization Detector) are based on the principle of photoionization. The sensor module consists of an ionizing lamp and a detector. The ionizing lamp generates high-energy UV radiation that ionizes gas molecules with a certain energy by extracting electrons from them. The excitation energy can be configured by selecting the ionizing lamp in the PID sensor.
The detector in the sensor measures the number of ions thus generated by electrodes hit by the ionized molecules. The electrical current thus generated can be measured and is proportional to the concentration of VOCs in the air. The air-Q converts this current into a measured value.
Which VOCs can the air-Q PID sensor detect?
A VOC PID sensor is capable of detecting a wide range of Volatile Organic Compounds, including solvents such as formaldehyde, toluene; hydrocarbons; vapors from pesticides; industrial chemicals and other potentially harmful substances. By selecting the type of ionizing lamp and configuring the response factors, well over 1,000 different VOCs can be stably detected and quantified.
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How does the measurement with the VOC PID sensor in the air-Q work?
The PID sensor can be purchased as an additional sensor in the air-Q Science or as a separate additional sensor for retrofitting existing air-Qs. On request, we offer sensors with different ionizing lamps with excitation energies of 10 eV, 10.6 eV and 11.7 eV.
As with all air-Qs, data input is available via the air-Q smartphone app for iOS and Android, our air-Q web app, and data output via MQTT or CSV data export. Via configuration in the smartphone app or via a configuration file, different response factors for the PID sensor can be recorded in order to calibrate or use the sensor for the measurement of specific VOCs.
The air-Q PID sensor has a measuring range of 0 to 6,000,000 ppb with a resolution of 1 ppb. The UV lamp has a service life of at least 1 year - experience has shown that it is considerably longer. It can then be replaced without having to replace the entire sensor.
For whom is the air-Q with VOC PID sensor suitable?
The air-Q with PID sensor is primarily intended for professional use. Due to the amount of VOCs detected, the very wide measuring range and the high accuracy, it is perfectly suited for use in research and development. It is also conceivable to use it for industrial purposes, e.g. to robustly monitor the concentration of certain harmful or explosive gases even in non-air atmospheres.
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