Chapter 3 – Operation
TestEquity 3007C Temperature Chamber
Page 3-1
LN2 (Liquid Nitrogen) Boost Cooling (Option 0018)
!
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.
Liquid Nitrogen can be used to provide faster cooling rates or greater cooling capacity with
heavy or energized loads. It does NOT provide infinite cooling capability. For example, with a
25
pound load and a range of +85°C to −40°C, the chamber will cool at 8°C/minute without LN2
and 13°C/minute with LN2. However, it cannot transform the chamber into a “shock chamber”.
The chamber is configured to enable or disable the LN2 Boost Cooling System through Event 2
(Digital Output 2) in the F4 Controller, or the LN2 button in the F4T Controller. You must turn
this ON to enable the LN2 Boost Cooling System.
When the demand for cooling throttle is at least 50%, the temperature controller will energize the
LN2 Cooling Solenoid to inject LN2 into the chamber.
Purge
Optional 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.
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-0034)
Option TE-0031 is a prerequisite to provide the purge inlet functionality for Option TE-0034.
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 8 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 2 (Digital
Output 2) in the F4 Controller.
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 particular
conditions. A suggested starting setting is 4 SCFM.
