Fluke 1595A Thermometer User Manual


 
113
Troubleshooting
11 Troubleshooting
The purpose of this section is to help the user troubleshoot unexpected operation results. Use the following list
of problems and solutions to troubleshoot the issue. If the issue cannot be resolved using this section, contact
the nearest Fluke Authorized Service Center for additional support.
Problem Solution
Failure to produce valid measurements Check probe wiring. Use an ohmmeter to check continuity of the 4-wire
connection to the probe. Verify that one common pair of the 4-wire connection
is connected to P1 and C1 terminals while the other pair is connected to the P2
and C2 terminals.
Make sure the probe or resistor is connected to the same channel indicated by
the channel number in the upper left hand corner of the screen. Check to make
sure the correct reference resistor is selected. If an external reference resistor is
selected, ensure it is connected to either Rs1 or Rs2 on the back panel or either
channel 2 or 4 on the front panel.
Check the reference resistor denition to ensure it has been correctly
congured.
Try connecting a resistor or shorting the input to see if it measures. Try setting
the conversion to resistance rst.
If the Super-Thermometer is able to measure resistance correctly but displays
“. . . . . . . . . .” for temperature, there may be an error with the conversion type or
characterization coefficients. Check these carefully. The resistance of the probe
may be outside the range of the selected conversion type and coefficients.
Make sure probe leads are not shorted to other DWF connectors.
Run System Test to ensure the hardware is working properly. If System Test
does not pass, contact the nearest Fluke Authorized Service Center.
Multiple channels are enabled but only
one channel measures.
To measure multiple channels the unit must have the scan function enabled.
Turn on Scan Enable in the Scan Settings screen of the Measure menu.
Excessive measurement noise The current may be too low. Check the current setting by pressing the SETUP
key and viewing the excitation current setting for each channel.
The reference resistor selection may be incorrect. Check the assigned reference
resistor for each channel by pressing the SETUP key and viewing the Rs
selection.
A faulty measurement connection can be a source of noise. Check the
connection by gently tugging the connector on each wire and inspecting for
possible wire breaks.
The digital lter may not be congured correctly.
The Timing Settings may be too fast. Try setting the Sample Period to a longer
setting. This may also help when scanning multiple channels.
Make sure there are no strong sources of electromagnetic interference near the
Super-Thermometer or devices connected to it. Use measurement cabling that
is shielded. Attach the shield wire of the cable to the Ground DWF connector.
Try attaching a ground wire between the Ground DWF connector on the Super-
Thermometer and the chassis of the temperature source.
Room temperature variations or air drafts near the Super-Thermometer may
cause measurement instability. Locate the instrument in a stable environment.