Chapter 8 – Maintenance
TestEquity 1016C-1027C Temperature Chamber
Page 8-5
How to inspect the electrical compartment.
1.
Disconnect the chamber from the power source.
2.
Turn the Main Disconnect Switch to the OFF position.
3.
Remove the lower door retaining screw located on the right side. Open the lower door.
4.
Check for loose components, loose wires, burned insulation near terminals, and burned or
excessively pitted contacts on contactors.
How to clean the condenser.
1.
Disconnect the chamber from the power source.
2.
Turn the Main Disconnect Switch to the OFF position.
3.
Remove the lower door retaining screw located on the right side. Open the lower door.
4.
Clean the condenser and desuperheater fins with a vacuum cleaner.
NOTE:
You may need to clean the condenser more frequently if the chamber is in a dusty
environment. You may be able to clean the condenser less frequently if the chamber is in a very
clean environment.
How to verify the calibration.
!
CAUTION:
TestEquity does not recommend performing the controller calibration
procedures unless you have verified that the controller is actually out of
calibration.
TestEquity recommends verifying the calibration before attempting to actually perform a
calibration. The state-of-the-art instrumentation used in TestEquity chambers is of the highest
quality and seldom goes out of calibration. If you try to calibrate the instrumentation before
determining that calibration is necessary, you may make it worse if done incorrectly.
Variations in temperature throughout the chamber interior are NOT a measurement of controller
accuracy. These variations, called “gradients”, are a function of the physical design of the
chamber and its airflow, the characteristics of the test sample, and how it is oriented in the
chamber. You cannot “calibrate” to improve gradients. The common practice of measuring
multiple points in the chamber and adjusting the temperature controller’s calibration to correct
for these errors is incorrect! The correct way to adjust what the temperature controller “displays”
compared to what is measured at some point other than the controller’s sensor, is with the
“Calibration Offset” parameter. See the F4T or F4 Temperature Controller User’s Manual for
details. Calibration verification should be performed with the Calibration Offset set to 0.0 (zero).
Total system accuracy in the chamber includes the controller plus the thermocouple wire
accuracy. Total system accuracy over the chamber’s operating range is typically ±1.55°C, ±1
LSD or a theoretical total of ±2.55°C. The easiest way to verify the instrumentation accuracy is
with an independent calibrated temperature sensor and display. Place the sensor inside the
chamber, near the chamber’s conditioner fan grille. If the readings agree within the specified
limits, then no calibration adjustments are necessary.
