d. Recommendations. Recommendations to correct deficiencies covered by
the discussion will be made by the AMCC when it is appropriate.
These
recommendations will be forwarded to the audited facility immediately after
completion of the USAMCC analysis of the audit.
7.
Frequency/Time Measurements.
a. US Army measurements of frequency/time will be referenced to the
Department
of
Defense
(DOD).
Controlled
radio
transmissions
of
frequency/time maintained by the US Naval Observatory (USNO).
AMCC may
authorize the use of other transmissions when the DOD transmissions cannot
be adequately received.
b. Traceability of measurement accuracies within the Army calibration
system is normally from the secondary transfer calibration team, through the
AACL, through the USASL, and subsequently to NBS.
Frequency/time is the
exception in that Army calibration activities derive the accuracy of these
measurements through very low frequency (VLF) radio signals transmitted by
the USNO.
The USASL maintains the Army frequency standard but has no
participation in normal frequency/time measurement accuracies of AACL or
transfer teams. Army calibration facilities will use DOD VLF radio signals
or the DOD VLF "OMEGA" signals for frequency calibration whenever possible.
The use of other VLF transmissions must be approved by the AMCC.
c. The technical procedure for assuring traceability of frequency/time
measurements to the DOD standards is contained in TB 750-115 and will be
used by calibration facility.
8.
The Army VOLT program for Army calibration facilities.
The accuracy
of the Armys standard volt at the USASL is transferred to a secondary
reference facility by movement of a transport standard volt to the
calibration facility. This transport standard volt is compared against the
facility's standard volts and then returned to the USASL.
The comparison
readings are forwarded to AMCC who review them and determine the value of
the facilities standard volt.
a. General.
Figure 2 indicates an ideal flow of the volt within the
calibration system.
It indicates an ideal traceability chain from the
"Legal Volt" at the National Bureau of Standards (NBS) to the lowest level
of the Army Calibration System. As the chart indicates, the US Army Volt is
linked to the US Legal Volt at NBS with procedures of the NBS Volt Transfer
Program and transportable standard cell enclosures. The AACL Volt is linked
to the US Army Volt at the USASL with procedures of TB 750-245-8-3 and
transportable standard cell enclosures supplied and controlled by the USASL.
Local surveillance of cells in the reference and working groups at the AACL
will be performed in accordance with procedures of the TB.
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