instructors
and screen all incoming technical and regulatory material
relating to
calibration techniques, procedures, or equipment modification.
They assist
in interpreting and implementing directives and instructions as
necessary.
Overall training requirements and arrangements for school
training of
calibration personnel are the responsibilities of the operations
office.
h. The secondary reference laboratory must have an environmentally
controlled area for the secondary transfer standards to be put in so they
have time to reach ambient temperature before they can be calibrated. The
period of time is usually 24 hours. This will vary by instrument type. A
log-in and log-out register may be maintained to keep a record of the
soaking time, specialist, and the amount of time required to calibrate the
item.
i. Laboratory supervisors will assure that temperature and humidity
recording systems are maintained in continuous operation as outlined in TB
750-117/TB 750-25.
An electrically driven recording chart will be
functioning continuously. The recording temperature chart indicator must be
visible so a calibration specialist can keep a check on it at all times and
not interrupt his work.
4.
ENVIRONMENTAL CONDITIONS
Secondary Reference Standards.
In any highly accurate measurement,
temperature and other environmental conditions are factors.
Therefore, in
order for reference standards to operate at their calibrated values they
must be used in a known stable environment.
The following are the
requirements.
a. Temperature.
(1) Dimensional or optical standards: 20C 1C (68F 1.8F).
(2) Physical standards, other than dimensional or optical, may be
calibrated with dimensional, optical, electrical, or electronic standards
and operated satisfactorily at the temperatures specified for those
standards.
23C
1C
(3) Electrical
or
electronic
and
standards:
+
(73.4F + 1.8 F).
b. Humidity.
The relative humidity will be maintained between 20% and
50%.
c. Dust.
Dust particle count will be:
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