255.809 Leaks: instrument sensitivity verification.

Each instrument utilized for leakage surveys and investigations must be tested against a known sample or in accordance with the manufacturer's recommended instructions as follows:#

(a)after any repair or replacement of parts other than normal maintenance;#

(b)once every three months for CGI's and solid-state leak detection instruments and yearly for hydrogen flame ionization (HFI) instruments; and#

(c)any time it is suspected that the calibration has changed.#