PID Correction Factor Lookup

CF/RF values for 300+ compounds across RAE Systems, Industrial Scientific MX6, IGD/GenSenova, and Dräger instruments

Correction Factor (CF) / Response Factor (RF) — PIDs are calibrated to isobutylene (CF = 1.0). To obtain the true concentration of another compound:
True concentration = PID reading × CF. CF > 1 means the instrument underreads; CF < 1 means it overreads. NR = no response (compound ionisation energy exceeds lamp energy).
Search for a compound above to view correction factors across manufacturers.
Enter the compound, lamp energy, and PID reading to calculate the true concentration. Select the manufacturer whose CF values you want to apply.
Compound CAS IE (eV) RAE 10.6 RAE 9.8 RAE 11.7 MX6 10.6 IGD 10.6 Drg HC Drg LC

How PIDs work

A photoionization detector (PID) ionises gas molecules using UV light and measures the resulting ion current. PIDs are calibrated to isobutylene (2-methylpropene, CAS 115-11-7), assigned a CF of 1.00. Because different compounds ionise with different efficiency under the same lamp, a correction factor is required to convert the displayed reading to the true concentration.

Correction Factor (CF) = Response Factor (RF) — The terms are used interchangeably across manufacturers. RAE Systems uses CF; MSA, Industrial Scientific, and Dräger use RF. The calculation is identical: True concentration = PID reading × CF.

NR (No Response) — The compound's ionisation energy (IE) exceeds the lamp photon energy. The compound cannot be detected with that lamp.

Lamp energies: The most common PID lamp is 10.6 eV. High-sensitivity lamps at 11.7 eV can detect compounds with higher IE (e.g. some halogenated solvents), but degrade faster and are humidity-sensitive. Low-energy 9.8 eV lamps reduce sensitivity to common interferences.

Dräger sensor variants: The PID HC (high concentration) is suited to ppm-range work; the PID LC ppb version has a smaller measurement cell for sub-ppm detection. RF values differ between the two.

Manufacturer Instrument Lamp (eV) Source Compounds
RAE Systems MiniRAE, ppbRAE, MultiRAE 9.8 / 10.6 / 11.7 TN-106 262
Industrial Scientific MX6 iBrid 10.6 PID Response Factors table 115
IGD / GenSenova SL-031 10.6 CF table SL-031-2 141
Dräger X-am 8000 10.6 Substance list (PID HC + LC ppb) 90
MSA ALTAIR 5X 10.6 Compound library (RF device-stored) 118 (no published RF)
CF values are sourced directly from manufacturer technical documentation. Values are for informational purposes only; always verify against the current manufacturer datasheet for your specific instrument and lamp. Humidity, temperature, lamp age, and calibration gas concentration all affect accuracy. This tool does not replace site-specific calibration procedures.