Section 3
3-2
Operation
Two-Stage
Condenser
Peltier Cooler
Reservoir
Pump
Radiator
Cooling Water Path
Valve
Pump
Filter
Air Inlet
Rotameter
Rotameter
Air Output
Port #1
Air Output
Port #2
Air Flow Path
Figure 3-1. Path of air and water flow through the LI-610.
Water Flow In
the LI-610
An internal radiator assembly is used in the LI-610 to provide a means
of dissipating the heat generated by the two Peltier coolers attached to
the condenser block (Figure 3-1).
The Peltier coolers are thermoelectric devices which absorb or liberate
heat, depending upon the direction of electrical current flow through the
junction of dissimilar metals.
When the coolers are switched ON, current flows in a direction which
causes heat to be absorbed or generated, based on the position of the
TEMPERATURE SET
controls on the front panel, thereby lowering or
raising the temperature of the water present in the block. The condenser
blocks are copper, which is an excellent conductor of thermal energy. A
continuous flow of water between the coolers and the radiator allows
excess heat to be dissipated. A precision platinum Resistance-
Temperature-Detector (RTD) is used to monitor the temperature of the
condenser block (the condenser temperature is limited to +50 °C).
