Installation and Operating Guide
Smart
® Desiccator
Copyright 2017 Terra Universal Inc. All rights reserved. • Revised August 2020 • Document No. 1800-16
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: (714) 578-6000 • FAX: (714) 578-6020
4
After a four-second delay, during which time no buttons are pressed, the unit will store the new set point and return to
normal operation, displaying the current RH level.
Recommended Minimum Settings:
Although the RH level can be specified anywhere between 0 and 99.5% RH, the
practical set point range is from room ambient (highest setting) down to the RH of the supply gas (lowest setting).
Because the unit is accurate to ± 2%RH, your set point should be at least 2% above zero (recommended minimum
setting is 4%). Otherwise, the system could attempt to attain a negative reading and remain on high purge mode all
the time.
4.0
Changing Set-Up Mode Parameters
Refer to the descriptions above for each of the set-up mode parameters. Before proceeding, make sure that the
Smart® Desiccator is connected to a ¼” nitrogen gas (or other process gas) supply line externally regulated at 10 –
20 PSI.
A.
Relative Humidity Offset
1.
To change parameter settings, you must first enter the Set up Mode. To do so, disconnect the 12VDC plug
from the side of the unit.
2.
While pressing and holding both red buttons (labeled “A” and “B”), reconnect the 12VDC plug to the power.
3.
Release the “A” button only. The LED will show “
RH
” to indicate the Relative Humidity Offset Parameter.
4.
Release the “B” button. The display should read the factory value (see below table). Press the “A” button to
increase this value. The settable range is -10 to +10. When the upper range limit is reached, displayed
values will cycle to the lower range limit.
Humidity Module Part# Default Value
1911-30B
0%
1911-30C
+2%
B.
RH Hi Alarm (Default = 180 seconds)
1.
To advance to the Open Door parameter, press and hold the “B” button. The display should read “
RH
”.
2.
Release the “B” button. The display should indicate “180”, the factory setting in seconds. Press the “A”
button to increase this value. The settable range is from 0 – 255; when the value reaches 255 it will cycle to
“0” and continue climbing. Release when the desired alarm delay appears
C.
Identification Parameter (default = 0)
1.
Press and hold the “B” button again to view the Identification Parameter, which is not used with Smart®
Desiccators.
D.
Purge-Off Delay (default = 30 seconds)
1.
To advance to the Purge-Off Delay parameter, press and hold the “B” button. The display should read
“
purgG
”.
