Fluke 7341 User Manual page 75

7341 Calibration Bath
User's Guide
72
Problem
The display flashes "cutout" and
an incorrect process temperature
The displayed process tempera-
ture is in error and the controller
remains in the cooling or the
heating state at any set-point
value
Causes and Solutions
The problem may be that the controller's voltmeter circuit is not func-
tioning properly.
•
A problem could exist with the memory back-up battery.
If the battery voltage is insufficient to maintain the mem-
ory, data may become scrambled causing problems. A
nearby large static discharge may also affect data in
memory. Verify that the parameters on the Report of
Test. are accurate. Cycle the power off, disconnect the
bath from AC, and then restart the bath.
•
If the problem reoccurs, the battery should be replaced.
Contact an Authorized Service Center (see Section 1.3,
on page 5) for assistance.
•
If initializing the memory does not remedy the problem,
there may be a failed electronic component. Contact an
Authorized Service Center (see Section 1.3, on page 5)
for assistance.
•
The controller may need to be reset. Perform the follow-
ing Factory Reset Sequence.
Factory Reset Sequence. Hold the SET and EXIT but-
tons down at the same time while powering up the
instrument. The instrument display shows '-init-', the
model number, and the firmware version. Each of the
controller parameters and calibration constants must be
reprogrammed. The values can be found on the Report
of Test that was shipped with the instrument.
Possible causes may be either a faulty control probe or erroneous
data in memory.
•
The probe may be disconnected, burned out, or shorted.
The probe is located inside the stirrer motor cover.
•
Check that the probe is connected properly. The probe
may be checked with an ohmmeter to see if it is open or
shorted. The probe is a platinum 4-wire Din 43760 type.
The resistance should read 0.2 to 2.0 ohms between
pins 1 and 2 on the probe connector and 0.2 to 2.0
ohms between pins 3 and 4. It should read 100 to 300
ohms between pins 1 and 4 depending on the tempera-
ture. If the probe appears to be defective, contact an Au-
thorized Service Center (see Section 1.3, on page 5) for
assistance.
•
If the problem is not the probe, erroneous data in mem-
ory may be the cause. Re-initialize the memory as dis-
cussed in the problem 'The display flashes "cutout" and
an incorrect process temperature'. If the problem re-
mains, the cause may be a defective electronic compo-
nent, contact an Authorized Service Center (see Section
1.3, on page 5) for assistance.