TestEquity 123H, Operation And Service Manual

Page: 30 / 77

Chapter 4 – F4 Temperature/Humidity Controller
Page 4-10 TestEquity 123H Temperature/Humidity Chamber
Purge
GN
2
(gaseous nitrogen) Purge or optional 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
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 (TE-0017)
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.
This system requires a 5 cfm supply air flow rate at 100 psig (175 psig max).
Figure 4.4 – Dry Air Purge System Installation
Compressed Air Inlet to Dry Air System.
Shutoff valve on the Dry Air System is shown in the off
position. Valve must be in the on position to operate.
Purge Inlet from Dry Air System
Connect to PURGE fitting on chamber.