Photo-ionization detectors (PID) are a valuable tool when measuring low level concentrations of organic vapours and hydrocarbons. Organic and inorganic compounds can be measured by a PID in levels anywhere from parts per billion (ppb) up to 10,000 parts per million (ppm).
Introduced originally as a handheld measuring device, photo-ionization sensors are now found in both single gas and multi-gas gas detection instruments.
The increase in the use of the PID’s for measuring VOC’s (volatile organic compounds) in different environments creates potential errors in the use of this valuable tool.
Like all sensor types there are a variety of issues, such as cross sensitivity or interference with photo-ionization (PI) sensors, which users must be aware of in order to use the instrument correctly.