TB 9-4931-537-24
CROSS-CHECKS
5. Purpose. This section provides guidance and procedures applicable to the cross-check
of measurement standards.
6. Applicability. This section is applicable to all transfer level support activities, GOCO
facilities, and ARNG.
7. Policy
a. Activities that operate in a fixed configuration (those that do not travel to customer
sites) will perform cross-checks on designated measurement standards which are supported
by another activity. Cross-checks will be performed, at a minimum, at receipt of equipment
prior to placing the standard into service and then again prior to submitting standard for
calibration.
b. Mobile activities that travel to customer sites, regardless of distance, will perform
cross-checks on designated measurement standards which are supported by another
activity. The standards will be cross-checked, at a minimum, when the activity arrives at
the first location where the support mission is to be performed (prior to performing the first
calibration) and then again after completing the last calibration prior to departing that
supported area. If travel to other sites is required then this cycle will be repeated until
such time as the standards are to be submitted for calibration. At that time a final cross-
check will be required prior to submission.
c. Additional cross-checks will be performed when any indication of problems creates
doubt of the credibility of measurements, or at any time the accuracy of a measurement is
suspect.
d. Cross-check requirements are not justification for the acquisition of additional
standards.
e. Whenever the ACL calibrates a standard and finds an out-of-tolerance condition,
this must be reported to the TSA to enable them to perform actions specified in paragraph
9 c below.
8. Equipment to be Cross-Checked
a. Standards requiring periodic cross-checks are: Calibrator, Fluke, Model 5720A/( );
Amplifier, Fluke, Model 5725A/( ); and Multimeter, Agilent, Model 3458A/( ). These
standards are also listed at the top of table 1 (at end of this Section). Additionally, the
organizational chief is responsible for maintaining and assuring all calibration standards
and equipment are in proper calibration and operating condition. Therefore, the chief may
cross-check additional standards deemed necessary.
b. If an organization does not possess specific items of equipment, listed in a above, the
most accurate dc voltage, ac voltage, and resistance standards which receive support by a
higher level calibration activity, will be cross-checked.