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VOC sensors and how MiniPID 2 works

15 June 2020

MiniPID sensors manufactured by ION Science can be used to detect VOCs.

There are three main VOC sensors that are used to detect VOCs, these include:

  • Photoionisation detector (PID)
  • Flame ionisation detector (FID)
  • Metal oxide semi-conductor sensor (MOS)

ION Science's MiniPID 2 is made up of three key components: the body, UV lamp, and the electrode stack.

When VOC gas enters the detection chamber, UV light (ultraviolet) energies the molecules, releasing negatively charged electrons. Therefore, the VOC molecule becomes positively charged.

The negatively charged electrons are attracted to the positive electrode and positively charged molecules are attracted to the negative electrode.

This results in a tiny electrical current that increases with gas concentration.

ION Science says many PID sensors give false readings in the presence of humidity as moisture creates a conductive path in the electrodes.

However, the MiniPID 2 uses patent fence electrode technology that blocks the conductive path, which practically eliminates the issue.

The MiniPID 2 also has an anti-contamination filter, this blocks airborne particles entering the detection chamber.

It also helps retain tiny amounts of ozone generated in the chamber.

Ozone actively cleans the electrode stack ensuring optimum performance is maintained.