Many sensors and other measuring devices such as PIDs can be affected by environmental conditions, and humidity is a major one. Humidity can affect PID sensors by either decreasing the response time due to VOCs participating in a quenching effect as humidity increases, leading to false-negative readings, or by a drifting response when very high humidity is in the atmosphere, resulting in a false-positive response. 

Humidity is defined as the amount of water vapor present in the atmosphere or in a given space. Water vapor is known as the gaseous state of water and is invisible to the human eye, even though we can feel it in certain environmental conditions. Warmer weather causes water to evaporate more quickly, which can be identified in geographical locations near oceans or massive bodies of water. Humidity can be more specific, however, and is known as relative humidity. Relative humidity is the ratio, usually expressed as a percentage, of the amount of atmospheric moisture present relative to the amount that would be present if the air was saturated. In this discussion, relative humidity is dependent on moisture content and temperature.  

There are several ways to combat humidity effects on PID sensors, such as adding desiccant tubes to dry the gas stream or use a humidified calibration gas to equilibrate it with the humidity present, but those options still have their limitations. Manufacturers recommend field calibration for their PIDs by using isobutylene due to providing close results when compared to a device not in a humid environment, and is an inexpensive option that is readily available. But, this method is only effective for portable devices. 

Selecting the right device for humidity operations within your industry is the best way to combat the effects of humidity on PID sensors. If your application has the risk of humid environments, look to DOD Technologies to provide solutions for you. We offer a range of gas detection systems for your needs and can advise the best one for your application as well as suggestions to decrease the risk of humidity on your gas detection system. Our expertise from years of experience and industry knowledge can help you decide the best portable or fixed detection system while keeping in mind humidity environments. 

DOD Technologies values the safety of all personnel and work environments by offering a variety of portable and fixed gas detection systems for your needs. Do you have a question regarding humidity and its effects on your application? With more than 150 years of combined instrumentation and application knowledge, DOD Technologies is prepared to offer its expertise and solutions for your toughest requirements while keeping you, your employees, and your equipment safe. 

Contact us today via phone at (815) 680-6086 or through our web form.

XP-3160 Portable Gas Detector