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The following step by step procedure should be followed when running the compressors to collect data.

  • Turn on data acquisition PC and data acquisition unit
  • Turn on external power supply to ambient condition sensors
  • Turn on both power supplies to sound pressure meter
  • Verify condensate drain hoses are in position to collect condensate
  • Flip compressor disconnect to ON position
  • Plug in watt transducer power cord
  • Bring up Bench Link program on PC and open appropriate setup
  • Check setup to confirm correct settings of each channel
  • Download set up to data acquisition unit
  • Monitor each channel to verify correct readings
  • When data acquisition unit and PC are communicating, sensors are working properly, and channel configuration is correct, the system is ready to scan
  • Record the date, compressor hours, loading hours, oil charge, and regulator hours in the compressor log book
  • Hit the start scan icon from Bench Link Software
  • Turn on compressor
  • Check oil level indicator on air receiver to verify proper oil charge

The following procedure should be followed when shutting down the compressor and data acquisition components.

  • Hit the compressor stop button (Not the Emergency Stop Button)
  • Wait for the compressor to unload and turn itself off
  • Hit the stop scan icon from the Bench Link Software
  • Label the data with corresponding file name
  • Record data file name in compressor log book
  • Turn off power supply to sound pressure meter
  • Turn off auxiliary power supply to ambient air sensors
  • Flip compressor disconnect to OFF position
  • Unplug 120 VAC supply to Watt Transducer

Handling the Data

The data will be labeled with the following file format. C1_aaa_01

The first two digits correspond to the compressor number. The next three letters correspond to the run number, and the last two numbers correspond to the channel number. Each individual channel is saved as a text file and copied via. ftp onto the uni versity’s server. Once all channels are on the server, an integration program can be run to determine the average value over a predetermined time interval. The integration program is given in Appendix I. The integration being performed is based on the routine by Gill and Miller, which performs a 3rd-order finite differentiating method using uneven time intervals. The integration program is designed to return all the integrated averages, the time interval of each integration, and the average of the whole data set. The output files of this integration program can then be imported into the Sigma Plotâ spreadsheet program. Once plots are arranged to display the data in graphical form, they can be called up as a template and the new data will be automatically fit into the previous setup. Examples of these plots are shown in Appendix E.

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Department of Mechanical Engineering
University of Wisconsin-Milwaukee
Post Office Box 784
Milwaukee, Wisconsin 53201-0784 U.S.A.

Please email John Reisel (reisel@uwm.edu ) with any questions or comments about his web site.

Last modified: May 26, 2004

Copyright © 1997-1999 by Dr. John R. Reisel and Dr. Kevin J. Renken.
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