Fluke 1594A Technical Manual page 124

1594A/1595A Super-Thermometer
Problem
Poor accuracy
Graph of measurements jumps or stair-
steps
The display shows negative resistance.
The USB memory stick does not work
Unit will not power up.
The display is in the wrong language
Screen is blank
Keypad does not respond
Resistance statistics field is blank when
measuring in ratio mode
114
Solution
The current may be too low causing poor signal to noise ratio or too high
causing excessive self-heating. 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.
The Timing Settings may be too fast. Try setting the Sample Period to a longer
setting. This may also help when scanning multiple channels.
The temperature conversion type or probe characterization coefficients may be
in error. Check each of the probe parameters carefully. Use the Test Calculation
function and compare the results with the probe's calibration report table.
Make sure probe leads are not shorted to other DWF connectors.
Verify the reference resistor calibration value is entered correctly.
Make sure the probe wires are properly and tightly connected
If using extremely long measurement cables, the capacitance in the wires can
affect the readings. Try setting the measurement timing parameter sample
period to the longest setting to allow for the measurement to settle.
Check the oven stability indicator on the Measurement screen. After 30 minutes
from power up the indicator should change from SETTLING to READY. If the
oven stability indicator never changes to READY, contact a Fluke Authorized
Service Center. The unit could still be used with an external reference resistor
since the internal oven has no affect when using external resistors.
This is normal if the temperature being measured is increasing or decreasing
faster than the digital filter is able to track. To eliminate this effect, temporarily
disable the digital filter.
The measurement cable is not connected correctly.
Plug the memory stick into the front panel USB port and wait for about 10
seconds for the system to recognize the device. When recording data to the
memory stick wait for the flashing read/write LED on the memory stick to stop
flashing before removing it.
Make sure the memory stick id formatted to Fat 32. This can be done by
inserting the memory stick into a personal computer and right clicking on the
drive letter of the memory stick and selecting properties.
Make sure the memory stick is compatible with the Linux operating system 2.6
or greater.
Make sure the main power switch located on the back of the unit is turned on
Check the fuses in the back of the unit
Check the power cord
If the Super-Thermometer is inadvertently set to the wrong language the user
can open the User Settings screen in English by pressing and releasing the
ENTER key and then pressing and releasing the SETUP key. Select the correct
language if necessary.
The screen saver may be on. Press any button to turn the screen back on.
The system may be in standby. Press and release the Power Standby key on the
front panel to bring the unit out of standby mode.
The keypad has been locked by a remote operation command. The keypad can
be unlocked by sending the following command to unlock it.
SYST:KLOC 0
When in ratio mode, the Super-Thermometer will not produce a resistance
reading. If both measurements are required, set the Super-Thermometer to
measure resistance and select ratio as one of the statistics fields.