Specifications
16
8 Turn on the “RH” STANDBY switch on the front panel.
This will not automatically turn on the dehumidification system. Turning on
the “RH” STANDBY switch only makes the dehumidification system
available to the microprocessor controller.
When the controller tells Dehumidification System to activate, the small
red LED on the lower right side of the microprocessor display will light.
The internal air pump will begin moving. The pump will draw moist air from
the Chamber working space and force it through the desiccant column.
The dried air will then be returned to the chamber.
10. The microprocessor controller will determine the amount of drying needed
to maintain the desired set-point.
If less than the full drying capacity of the Desiccant Dehumidification
System is needed, the controller will provide pulses of power to the unit to
limit the quantity of dried air coming into the chamber. The pump will be
turned on and off cyclically to obtain an average input of dried air less than
the full capacity of the Dehumidification System.
To achieve a smooth, even dehumidification process the humidity
microprocessor Cycle Time 2 (CYC.2) should be set to 2.0 seconds.
Longer cycle times will create longer “gaps” between dried air pulses. DO
NOT SET THE CYCLE TIME LESS THAN 1.0 SECOND. Shorter pulses
may damage the Model 561 pump.
2.2.2 Self-Regenerating Dehumidification System
The Model 578 Self-Regenerating Dehumidification System is capable of drying
the Model 518 Chamber from 50% RH to 12% RH in less than 3 hours, at room
temperature.
2.2.2.1 Description
The Model 578 Self-Regenerating Dehumidification System requires 50-
100 psi of air pressure at 2.6 cfm to operate. For normal, short term use
an internal 50 psi pump may be supplied. Since air must be provided
continuously either a separate air compressor or house air should be
used for long-term dehumidification applications to ensure long-term air
delivery reliability.
The basic Self-Regenerating Dehumidification System consists of a
high-pressure air pump (50 psi., minimum), a dual column self-
regenerating desiccant dryer utilizing molecular sieve desiccant, and a 3-
way control valve. The high-pressure pump and dual column dryer