Precautions When Selecting Test Equipment; Precautions When Using Test Equipment; Periodic Checks - Ametek UPLC CU44-VER04 Applications Manual

When individual module maintenance is required, either at the factory or at the customer installation
(beyond the scope of routine alignment), the following procedures are applicable. Very little, if any, mod-
ification or repair can be done properly in the field. Therefore it is recommended that you contact the fac-
tory for a Repair Material Authorization (RMA).
6.1 Precautions When Selecting
Test Equipment
(See Chapter 4, Test Equipment for test equipment
specifications.)
To prevent damage to solid-state components:
1) Use transformer-type signal generators,
VTVMs and signal tracers, which isolate
the test equipment from the power line.
Whenever the test equipment uses a trans-
formerless power supply, use an isolation
type transformer. The test equipment
ground should be isolated from the ac
source ground.
2) Use multi-meters with at least 20,000Ωs-
per-volt sensitivity.
6.2 Precautions When Using
Test Equipment
1. Use a common ground between the chassis of
the test equipment and the transistor equip-
ment.
CAUTION
!
HIGH CURRENTS FROM A LOW-SENSITIVITY
METER CAN DAMAGE SOLID STATE DEVICES.
METERING TRANSISTOR
CAUSE DAMAGE.
FOR EXAMPLE: A BASE-TO-COLLECTOR
SHORT DURING TRANSISTOR OPERATION
CAN DESTROY THE TRANSISTOR.
Chapter 6. Maintenance
CIRCUITS CAN
Copyright © AMETEK
2. When testing transistors and diodes, give spe-
cial attention to the polarity of the meter leads.
For example: When measuring the forward
resistance of a diode using a meter that has the
internal battery connected to the metering cir-
cuit, be sure that:
• The lead marked ( – ) touches the diode
anode.
• The lead marked (+) touches the diode
cathode.
3. When checking circuits with an oscillograph-
ic probe, be sure to discharge any built-up
capacitive voltage by touching the probe to a
ground before touching the circuit.

6.3 Periodic Checks

Every 12 months, take the following readings on
the UPLC™.
• Transmitted Power Output
• Reflected Power
• Receive Level
• Receive Margin
Additionally, we recommend cleaning & re-
adjusting any spark gaps in the channel such as in
the tuners and CCVTs.
We recommend that you keep a log book as a vis-
ible record of periodic checks, as well as a source
for indicating any gradual degradation in a unit's
performance.
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