IET Labs 1404 Series, Руководство по эксплуатации

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7
1404 Series
7 Maintenance
Chapter 4
MAINTENANCE
4.1 Preventive Maintenance
Keep the unit in a clean environment. This will help
prevent possible contamination.
1404’s are packaged in a closed case, which limits the
entry of contaminants and dust into the instruments.
If they are maintained in a clean or air-conditioned
environment, cleaning will seldom be required. In a
contaminated atmosphere, cleaning may be required.
4.2 Calibration
The 1404 units may be employed as stand-alone
instruments or as integral components of a system.
If used as part of a system, they should be calibrated
as part of the overall system to provide an optimum
system calibration.
4.2.1 Calibration Interval
The recommended 1404 Series calibration interval is
twelve (12) months.
The calibration procedure may be carried out by the
user if a calibration capability is available, by IET
Labs, or by a certifi ed calibration laboratory.
If the user should choose to perform this procedure,
then the considerations below should be observed.
4.2.2 General Considerations
It is important, whenever calibrating an 1404 unit, to
be very aware of the capabilities and limitations of
the test instruments used.
Recommended Instruments:
• Andeen and Hagerling AH2500A
or
• IET Model 1620 or 1621 Precision
Capacitance Measurement System
(bridge)
It is important to allow both the testing instrument
and the 1404 to stabilize for a number of hours at the
nominal operating temperature of 23
O
C, and at nomi-
nal laboratory conditions of humidity. There should
be no temperature gradients across the unit under test.