Chapter 3 – Operation
TestEquity 1016H & 1027H Temperature/Humidity Chamber
Page 3-7
Purge Option
GN
2
(gaseous nitrogen) Purge or Dry Air Purge can be used to reduce to possibility of
condensation in the chamber at low temperatures, or to achieve humidity control below a 6
°
C
dew point condition.
!
CAUTION:
Nitrogen cannot be detected by human senses. Nitrogen is non-toxic.
However, if adequate ventilation is not provided, nitrogen will displace air.
This can cause dizziness, unconsciousness or death without warning. The
chamber must be located in a well-ventilated area. Do not open the chamber
door with the GN
2
flowing.
GN2 (Gaseous Nitrogen) Installation (Option TE-0031)
Connect a supply of GN
2
with a maximum pressure of 100 psig to the 1/4-inch FPT fitting which
is designated PURGE on the rear panel.
Dry Air Installation (Option TE-0030)
Option TE-0031 is a prerequisite to provide the purge inlet functionality for Option TE-0030.
Connect the hose from the Dry Air
system to the fitting which is designated PURGE on the rear
panel. Connect a supply of compressed air to the 3/8-inch FPT shutoff valve of Dry Air system.
Connect the power cord from the Dry Air system to the DRY AIR POWER socket on the rear
panel. This plug must be twisted clockwise to lock it. The Dry Air system requires 13 cfm of
compressed air at 100 psig (175 psig max).
Purge Operation
The Purge
mode is enabled through the Purge button on the F4T Controller or Event 3 (Digital
Output 3) on the F4 Controller.
For low humidity control
•
Turn Event 2 (
HUMIDITY)
ON and Event 3 (
PURGE)
ON.
•
Purge gas
will feed when the F4T/F4 Controller cycles the dehumidification system. It will
cycle on/off as the workspace humidity approaches and reaches the low humidity set point,
or whenever dehumidification is necessary.
For low humidity control below +10
°
C
•
Turn Event 2 (
HUMIDITY)
OFF and Event 3 (
PURGE)
ON. The Purge
System will continue to
provide controlled dehumidification even though the humidity system is disabled.
Adjusting the Purge Flow
A flowmeter is located on the front panel to adjust the flow of purge gas into the chamber. The
flowmeter has a scale, calibrated in SCFM. The flow of purge gas should be adjusted to the
minimum amount required to obtain the desired drying in the chamber for your conditions. A
suggested starting setting is 4 SCFM.
