In any test application that requires an altitude profile, the ESS, Inc. programmable altitude control system can be used to precisely control vacuum chamber pressure from ground level to an altitude of 170,000ft. A typical altitude testing chamber is comprised of a vacuum chamber, vacuum pump and a vacuum measurement instrument such as a mercury manometer. The programmable altitude control system is comprised of a programmable vacuum profile controller, pressure measurement transducer, electronically controlled proportional valve and a vacuum hardware installation kit to allow simple installation into most vacuum chamber systems.
System operation is as follows:
The pressure transducer constantly monitors vacuum chamber pressure and compares this value to the desired vacuum chamber pressure set point value displayed on the controller. If vacuum chamber pressure drops below the set point value, then the electronically controlled proportional valve will begin to open allowing makeup air to enter the chamber in order to match chamber pressure to the controller set-point. If the vacuum chamber pressure rises above the set-point value, then the electronically controlled proportional valve will begin to close, reducing the makeup air that enters the chamber in order to match chamber pressure to the controller set-point. A switch on the front panel of the controller allows the proportional valve to be manually closed.
The vacuum controller is factory set to operate in Torr units but can be user configured to operate in Mbar units also. Advanced control features such as programmable ramp to set-point and ramp and soak profiling are standard. These features allow easy front panel programming of flight profiles with multiple controlled time to altitude and time at altitude steps. A serial or GPIB computer interface is available for automated test applications.