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What does a PID measure?

Supplier: Thermo Fisher Scientific Rentals
05 August, 2013

PIDs are "broadband" sensors that respond to a variety of organic and some inorganic compounds.

General class of compounds suitable for detection are Volatile Organic Compounds (VOCs). A PID is very sensitive and can accurately measure gases and vapours in low ppm, it is not a selective monitor – it has very little ability to differentiate between gases.


  • Hazardous Waste Monitoring
  • Soil Remediation – Underground
  • Storage Tanks
  • Real Estate Transfers
  • Environmental Remediation
  • Contaminated Air Treatment
  • Headspace Screening
  • Industrial Hygiene
  • Hazardous Materials Spills
  • Volatile Emissions from paint
  • Chemical Warfare Agent Detection by PID e.g. nerve agents

Other applications include:

Aircraft Wingtank Entry, Turpentine in pulp mills, marine applications, cargo tanks, container vessels, seaport inspections and fuel tanks.

All elements and chemicals can be ionised. But they differ in the amount of energy required.

Energy required to displace an electron and ionise a compound is called Ionisation Potential (IP), measured in electron Volts (lamp energy is also measured in eV). If the IP of the sample gas is less than the eV output of the lamp, then
the sample gas will be ionised.