Check And Replace Fuses; Performance Verification - Fluke ProcessMeter 789 Calibration Manual

789/787B
Calibration Manual

Check and Replace Fuses

To prevent possible electrical shock, fire, or personal injury, use only
the specified replacement fuses.
Both current input jacks are fused with separate 440 mA fuses. To determine if a fuse is
blown:
1. Turn the rotary function switch to
2. Plug the black test lead into COM, and the red test lead into the Ac input.
3. Using an ohmmeter, check the resistance between the ProcessMeter test leads. If
4. Move red test lead to .
5. Using an ohmmeter, check the resistance between the ProcessMeter test leads. If
If a fuse is blown, replace it as follows. Refer to Figure 1 as necessary:
1. Remove the test leads from the ProcessMeter and turn the ProcessMeter OFF.
2. With a standard blade hand screwdriver, turn each battery compartment door screw
3. Remove either fuse by gently prying one end loose, then sliding the fuse out of its
4. Replace the blown fuse(s).
5. Replace the battery compartment door. Secure the door by turning the screws one-

Performance Verification

To prevent electrical shock:
•
•
Calibration verification tests confirm the complete functionality of the ProcessMeter and
check the accuracy of each ProcessMeter function against its specifications. If the
ProcessMeter fails any calibration verification test, it needs calibration adjustment or
repair.
The ProcessMeter's performance and accuracy are specified for one year after
calibration at operating temperatures of +18 °C to +28 °C (64 °F to 82 °F), in relative
humidity to 90 %. The specifications assume the ProcessMeter has been warmed up for
5 minutes before use.
To perform the calibration verification tests, it is not necessary to open the case; no
adjustments are necessary. Merely make the required connections, source the
12
the resistance is about 1 Ω, the fuse is good. An open reading means that fuse F2 is
blown.
the resistance is about 14 Ω, the fuse is good. An open means that fuse F1 is blown.
counterclockwise so that the slot is parallel with the screw picture molded into the
case.
bracket.
quarter turn clockwise.
Only qualified personnel should perform calibration verification
tests that use high voltages.
Always place the calibrator in the Standby (STBY) mode between
tests and before handling the test connections or test cables.
 Warning
W
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 Warning