AERI Resistance Validation

Equipment Required

  • Large phillips screwdriver
  • Ball driver set
  • Calibrated resistor kit (2 boxes)

Precaution

  • The resistor boxes are sensitive to large changes in ambient temperature (e.g. heating from direct sunlight).  It is best to conduct the test with the boxes in a sheltered, stable thermal environment.  For best results, place the boxes in the location/environment where the test will be conducted about an hour prior to the test.

Procedure

Hardware setup

  1. Stop data collection and power OFF the instrument:
    1. Press ctrl-c up to 3 times in the black Cygwin window to terminate ingest.
    2. Switch off the power bar in the AERI back-end.
  2. Remove the front panel of the front-end enclosure
  3. Disconnect the ABB and HBB connectors from the 1.5ft extension cables going to the blackbodies
  4. Connect the ABB and HBB connectors to the respective ABB and HBB resistor boxes and lay the boxes on the bottom of the enclosure.
  5. Power ON the instrument

Software setup

  1. Ensure that instrument is in RS_3 mode.  The test will not work in 3body mode
  2. Ensure that calibKit.connected=false in the file c:\E-AERI\FTSW_EAERI.Config
  3. Delete the file c:\E-AERI\Data\EAERIHouseKeeping.hk
  4. Run FTSW_EAERI_GUI.bat
  5. In the bottom panel, enter
    • # of measurements = 1
    • # of coadded scans = 9999
  6. Click Start Acquisition
  7. Click Stop Acquistion after about 15 minutes
    • Verify that the resistance look OK as they are being acquired (see Table 1.)
    • 20 records are needed for the analysis.  A new record is acquired every ~30 s, so the test should take ~10 mins + initialization

Analysis

  1. In a cygwin window
    • cd /cygdrive/c/E-AERI/Data
    • python txt2hkspc.py EAERIHouseKeeping.hk --resistance
  2. Transfer the created file EAERIHouseKeeping_YYYYMMDD_HHMMSSS.csv to a computer with MS Excel
  3. Open EAERIHouseKeeping_YYYYMMDD_HHMMSSS.csv in Excel
    • Select all
    • Copy
  4. Open AERI_Resistance_Validation_Template.xls
    • Paste data into Bring in AERI HK File worksheet
    • Save as AERI_Resistance_Check_SNXXX_YYMMDD.xls
  5. Check to see if the results pass in the Resistance Check Summary worksheet
    • If all six thermistor values are IN Spec (green), then the test passes
    • If any of the thermistor values are OUT of Spec (red), then the test fails and should be repeated
      • Check to see if the 20 records used are stable or drifting (the average is used in the calculation)
      • If the values are drifting, then the temperature of the environment of the resistor boxes may not be stable enough
      • Repeat the test for a longer time, in a more stable thermal environment if necessary
      • If needed, txt2hkspc.py can be modified to output a larger number records than 20

Hardware packup

  1. Power OFF the instrument
  2. Disconnect the resistor boxes
  3. Reconnect the ABB and HBB connectors to each extension cable
  4. Replace the front panel onto the AERI front-end
  5. Power ON the instrument and resume data collection

Table 1. Nominal resistance values and acceptable thresholds.  Values in Ohms

ABB HBB
top apex bottom top apex bottom
 Min R  98,947  124,931  799,464  2,759.1  9,896.0  12,494.8
 Nominal R  99,000  125,000  800,000  2,760.0  9,900.0  12,500.0
 Max R  99,053  125,069  800,536  2,760.9  9,904.0  12,505.2