General Methods Corporation  (GEMCO)
Morton, IL 61550  

Licensed and Bonded


High Altitude Shipping Simulator



The HASS simulates shipping a packaged box of dry goods at high altitudes. The number of peaks, the heights of the inclines (or peak), the ramp speed (or rate), and the time at the peak are configurable through the controller.

The vacuum level of the chamber is controlled by modulating a proportional valve.  The proportional valve's input is compressed plant air that is regulated down to approximately 60 psi.  Acceptable input air regulator pressures are 55 to 80 psi.  Lower pressures will not allow enough vacuum to build in order to simulate 12,000 feet of altitude.  The proportional valves output is connected to the input of a Venturi vacuum generator different vacuum levels and ramp rates can be achieved.  A graph of sample test run is shown on the last page of this document.

The HASS controller monitors the vacuum level and current rate of change of the vacuum during the test.  As these parameters vary, the command to the proportional valve changes to compensate for the error.  This allows the control to work under varying input pressures and with the varying packages under test. 

A vacuum transducer measure the amount of vacuum in the chamber and generates a 1 - 5 V analog input that is measured by the controller.  The proportional valve is controlled by a 0 - 10 V output on the controller.

The controller setup allows the user to configure multiple peaks.  Each peak has a height, ramp, and hold parameter.  The controller will execute each peak in sequence.  Once the controller finishes the hold time for the last peak the controller will ramp down to 0 ft. at the ramp rate for the last peak.

  HASS Controller

The HASS uses a Unitronics 570 PLC color touch screen.

The chamber will hold packaged product and simulate atmospheric pressure conditions while traveling to/through different altitudes. The chamber is controlled by a proportional regulator that feeds a venture type vacuum generator and monitored by a vacuum transducer. The proportional regulator is controlled by a feedback loop. The programming in the controller will allow the operator to define altitudes, ramp times and hold times. Operator can define a test of up to 5 steps example below:

   RAMP TIME           TARGET ALTITUDE             HOLD TIME

    00:04:00                  10000 feet                             00:30:00

    00:02:50                    5000 feet                             00:45:00

    01:00:00                  10000 feet                             01:00:00

    00:05:00                    8000 feet                        

    00:03:00                          0 feet                                                  


The program will provide a graphical representation of the altitude vs. time, as well as elapsed time and remaining time during a test.


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