Troubleshooting
6-1
Section VI.
Troubleshooting
This section summarizes some things that might go wrong, and suggests
what to do about these problems should they occur.
Instrument Can't
Maintain Dew Point
A dirty water filter screen can cause the LI-610 to produce a squeaking
noise every few seconds, condensation in the radiator housing, and an
inability for the instrument to maintain the chosen dew point.
See Section 5, Internal Water Filter Screen, for instructions on how to
clean the water filter screen.
Instrument Can't
Achieve Setpoint
Below Ambient
Temperature
In some cases the LI-610 may be able to achieve a temperature setpoint
above the ambient temperature, but is not able to achieve a setpoint
below ambient. This problem can be caused by a variety of problems:
1. Radiator and coolant reservoir are empty.
2. Coolant pump is off or not functioning properly.
3. Blockage in cooling water path.
4. Peltier coolers not receiving proper voltage.
First, make sure the radiator contains coolant - water should be visible in
the radiator fill tube.
Check to make sure that the coolant pump is working properly.
Disconnect the "To Cooler" line, power on the LI-610, and briefly toggle
the "COOLER" switch to the ON position. If the pump is working
properly, water will discharge from the "To Cooler" port. If water does
not discharge, contact LI-COR.
Check for a blockage in the cooling water path. Without coolant
circulating through the Peltier coolers to dissipate heat, they cannot
achieve a temperature target below ambient. There are two Peltier
coolers, one on each side of the condenser block. There are water lines
that connect the two coolers, and also run to and from the radiator. A
blockage can occur in any of the hose fittings that connect to the Peltier
coolers. To remove the blockage, disconnect either the "From Cooler" or
