OPERATION
Page 3-6
CHAMBER PERFORMANCE
The performance of your chamber is signi• cantly effected by the
characteristics of your test sample. Factors include size, material, shape,
weight and power dissipation if energized. The test sample should be
placed in the chamber in a manner that allows proper ventilation. Air • ow
enters in the top left of the plenum and exits the top right.
HIGH/ LOW LIMIT CONTROL (OPTIONAL)
If the chamber is operated with a live load (heat dissipating product),
protection should be provided. Provisions must be made to remove power
from the product being tested and from the chamber in the event the
chamber temperature exceeds safe limits for the product being tested.
When testing a dead load (non-heat dissipating product), protection need
only remove power from the chamber.
The High/Low Limit Control shuts down the chamber and product under
test operation if the preset temperature limits are exceeded. Should the
temperature go beyond these limits, an audible alarm sounds and the
chamber shuts down. The Limit Control is a high and low limit control. It
accepts an input from a single Type "T" thermocouple to sense process
temperature. An LED display provides process temperature or limit set
point information. Discrete LEDs tell the operator the status of the unit.
High and low limit set points are user selectable at the front of the panel.
The output device is a six amp mechanical relay. The High/Low Limit
Control incorporates auto power reset. In a non-limit condition, auto
power reset will automatically energize the output relay and silence the
audible alarm when power is applied. If a limit condition exists, the output
relay will latch in a de-energized state and the audible alarm will sound.
The output relay can be re-energized and the audible alarm silenced
by the front panel "Reset" switch being depressed one time only when
the limit condition no longer exists. The "Reset" should be depressed a
second time to reset the alarm. The limit has three alarms that must be
set up the same to energize all alarm contacts at the same conditions.
Alarm 1 shuts down the chamber. Alarm 2 sounds the audible alarm.
Alarm 3 is used to de-energize the test product.
If other devices are used to
measure humidity or temperature
within the chamber, such as a
chart recorder (optional), the
temperature readings between
the chamber controller and the
chart recorder will vary slightly
due to the tolerances between the
two devices and their individual
sensing elements.
NOTE
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