Supplemental Manual
High-
IsoDry™ RH Control System
©
Copyright 2017 Terra Universal Inc. All rights reserved • Revised November 2020 • Document No. 1788-26
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: (714) 578-6000 • FAX: (714) 578-6020
7
3.0
Operation
Dual Purge System Operation
1.
Zero Calibration
: This routine is run before shipping to ensure that the pressure sensor that activates the Low
Pressure Alarm is properly calibrated. You need to run the routine only if the Low Pressure Alarm is activated
even though the Dual Purge is connected to a nitrogen supply with at least 30 psi of pressure.
To perform the zero calibration routine, disconnect the incoming gas supply line (Any pressure on the internal
pressure transducers will be subtracted from the reading during normal operation, resulting in incorrect low-
pressure alarms).
Press and hold SET and UP buttons while turning on system power. The display will indicate "CAL" and then
automatically set the zero value.
2.
Initial Programming
: Turn ON the Dual Purge System while depressing SET (the left button on the front control
panel). Each time you release and then press and hold the SET button, you will advance through the following
control functions. Use UP/DOWN to change default settings (shown in parentheses):
Prg 1
Purge Delay (minutes): Number of minutes high purge remains active after door is closed (default: 0)
Prg 2
Purge Delay (seconds): Number of seconds that the high purge remains active after door is closed
(default: 5). If operating the Dual Purge without a NitroWatch, you should increase this setting to 60.
door
After switching to high purge, the number of seconds to delay before turning on the beeper alarm.
beeP
State of the BEEPER enable (default: ON)
Glo
Activates GLOVE BOX control mode--Press UP to turn ON and proceed to glove box pressure setting,
DOWN to turn OFF (default: OFF). In GLOVE BOX mode, this setting lets you adjust the pressure
(milli-inches WG) at which the high purge is activated (default: 0.2). See “zero calibration” above.
DonE
Settings are complete; press SET once more to begin operation.
Made a mistake?
To reset the system, turn the system OFF while in setup mode and restart while holding the
SET button.
3.
Operation Display Functions:
After completing initial programming, press the specified button to view these
operating conditions:
High Purge Bypass: Press and hold SET
In some applications (especially using fine powders in a glove box), you may wish to deactivate the high purge
function, which could create turbulence. To do so, press DOWN while holding SET. To activate high purge, hold
UP while holding SET.
Incoming Line Pressure: Press and hold UP
(displays line pressure in PSI)
Turn the pressure regulator (the round knob on the right side of the Dual Purge control panel) until the pressure
gauge reads 30 psi (for bench-top desiccators) or 40 psi (for larger standing desiccators). Note that regulator
knob is reverse-threaded: rotate clockwise to open the valve and increase pressure, or counterclockwise to close
the valve and reduce pressure. For safe operation, pressure should be externally regulated below 70 psi.
