1.1 This practice covers the calibration of transmission densitometers used to perform radiographic film density measurements (see Note 1.) 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Note--For further information on the design and use of densitometers, the following literature is suggested as additional background information: Guide E94 and ANSI documents PH2.19 and PH2.36.