This section describes the requirements for flame ionization detectors (FIDs) used to measure hydrocarbons.

(a) Fuel the FID with a mixture of hydrogen in helium and calibrate it using propane.

(b) If you use a heated FID (required only for diesels and two-stroke, spark-ignition engines), keep the temperature 191 ±11° C).

(c) Use an overflow sampling system for heated continuous FIDs. (In an overflow system excess zero gas or span gas spills out of the probe when you are doing zero or span checks.)

(d) Do not premix the FID fuel and burner air.

(e) Make sure the FID meets accuracy and precision specifications in ISO 8178-1 (incorporated by reference in §1065.1010).