General Description

The ACC is an advanced test chamber used to simulate atmospheric conditions.   Variables include controlling pressure, temperature and relative humidity for testing and evaluating properties of  materials, processes and systems.

 Applications

• An electronics test lab certifying their product.
• A research organization testing material properties.
• An aerospace company simulating systems performance.
• An electronics company testing for moisture effects.

Test Types

The environmental tests can be conducted using  various environmental conditions.  Relative humidity profiles include steady state, steady state plus steps, square wave with ramp control (trapezoid), 

Chamber details

The environmental chambers are barometric pressure compensated, to protect your long duration testing with changes in the weather.  Significant errors can occur if this aspect is ignored.   RH probe calibrations can also be an issue, backup measuring systems may be needed if this is a critical parameter.  Long duration testing, depending on cycle rate and amplitude may require pauses for maintenance on systems without redundant vacuum pumps and RH probes.  Some high performance systems may require the use of exotic (expensive) working fluids.  Distilled water used in the RH production will need to be replaced as water vapor is removed from the chamber by the vacuum pumps.  Nitrogen purges may also be required for cold dry systems, as condensation will form ice in some working fluids.

Electronics

The ACC has numerous subsystems.  The power is distributed through a high current sub-panel located in the utility cart.  This power is used for such systems as the vacuum pumps, chillers and heaters.  Numerous sensors allow the system to interface with the computer.  The computer is a current generation running Microsoft^® Windows2000 Professional^®.  The analog interface electronics uses 16 bit precision.

Software

The Microsoft^® Windows2000 Professional^® based HMI (Human Machine Interface) software controls the ACC.  Concurrent multithreaded processes ensures high level of performance and self monitoring.  The fully Y2K compliant program running on Microsoft^® Windows2000 Professional^® is custom designed for this machine.  Data storage is in the form of an ASCII text comma separated values (CSV) file that can be read by any software that can read a text file.  The custom software semi-automates sensor calibration.  Data can be played back with a second program using a similar screen for review or demonstrations.

Versions