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About Volatile Organic Compounds (VOCs)

Volatile Organic Compounds, or “VOCs”, are organic chemicals that have a high vapor pressure under normal atmospheric pressures and temperatures. As a result, they have a low boiling point and readily evaporate into the atmosphere, creating potentially toxic conditions for workers. A VOC Detector measures the presence of VOCs and displays a value proportional to the amount of VOC detected, usually measured in ‘parts per million’.

VOCs occur naturally and exist in most all environments. VOCs include both naturally-occurring and man-made compounds. In industrial applications, VOC detectors are most often used to detect the presence of certain highly dangerous VOCs such as benzene, toluene, formaldehyde, and other gases that have been found to cause cancer or other serious health issues.

VOC Detection

The most commonly used method for detection of VOCs is a photoionization detector, often known as a “PID”. VOC molecules are complex and easily broken down by high energy photons. VOC sensors use a bright ultraviolet light source to knock electrons out of the VOC molecule; the electrons are measured and their flow indicates that VOC molecules are present at the sensor. Each specific type of VOC molecule has an ‘ionization potential’ (IP) value that represents the amount of energy necessary to liberate an electron; this value is measured in ‘electron volts’, or eV. PID sensors have a specified level of energy, also measured in eV, and in general, any compound with an IP value less than the sensor’s eV rating will be ionized and detected. For example, with a 10.6 eV sensor, the presence of benzene (IP = 9.24 eV) will be detected, whereas molecules water vapor (IP = 12.6 eV) will not. GDS Corp offers VOC sensors with both 10.0 eV lamps and 10.6 eV lamps. For help in choosing the proper lamp and calibration gas, please contact a GDS Corp applications engineer.

Contact GDS Corp. for More Information

To determine the best solution for a specific requirement for Gas Detection Equipment, please contact GDS Corp., a US manufacturer of Fixed Gas and Flame Detection Equipment located in Houston, Texas. Their many years of experience with Gas Detection Equipment as well as process and control instruments experience, can be a great resource to determine the best solution for a specific gas or flame detection application.