This practice is used to determine the number of useful impressions obtainable under normal operating conditions of a given typewriter or printer ribbon. It is suitable for service evaluation or research and development. This practice is generally not considered practical for manufacturing control specification acceptance because of the length of time required to obtain results.

Interpretation of the test result is to be made on a comparative basis, not on the basis of absolute values.

1.1 This practice covers the determination of the usable image producing life of an inked fabric typewriter ribbon or an inked fabric printer ribbon expressed as the number of impressions obtainable from a given unit.

1.2 This practice is not applicable to one-time typewriter ribbons such as carbon ribbons.

1.3 This practice is suitable for narrow printer ribbons with a width of 2 in. (50.8 mm) or less.

1.4 The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are for information only.

1.5 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.