Instrument Calibration/Adjustment; Figure 3 Pmt Adjustment Screen - Teledyne T640 Standard Operating Procedure

Note: Although the PMT verification is a very useful check that tells the user if the performance
of the monitor spectrometer is as expected, multiple checks of the PMT or individual
verifications that lead to too must span dust entering the monitors optics can itself lead to poor
performance of the monitors spectrometer and or RH sensor. Careful attention needs to be made
to ensure a minimum amount of span dust enters the sample tube during a verification and that
repeats of verifications are kept to a minimum.
For this procedure, ensure data are "in Maintenance"
1. Navigate to the PMT Adjust screen: >Home >Calibration>PMT Adjust.
2. Press the Start button on this screen to suspend normal data acquisition and start this
adjustment process.
3. Remove the T640 sample inlet.
4. Prepare the SpanDust™ bottle by uncapping the "air intake" tubing on the cap of the bottle.
5. Place the tube from the SpanDust™ bottle into the top of the Upper Inlet Tube for the
instrument.
6. Ensure that the silicone tube fits snugly inside the aluminum inlet tube, and do not allow the
bottle to hang, as it could dislodge the silicone tube from the inlet tube.
7. Gently tap the SpanDust™ bottle to barely agitate the contents just enough to allow the dust
to be pulled into the sensor, and allow 30 seconds for the Peak Channel reading in this
screen to respond.
8. Record the maximum Peak Channel, PMT Setting and Peak Channel Counts to the
"Monthly QC and Maintenance Sheet".
9. If the Peak Channel reading is acceptable 11.3 ± 0.5 (10.8 to 11.8 see Figure 3) record on
the Monthly QC and Maintenance Sheet.

10.2 Instrument Calibration/Adjustment

1. Pressure Sensor Calibration.
2. Flow Calibration.
3. PMT Adjustment using SpanDust™.

Figure 3 PMT adjustment Screen

10
DEP 03-21
Revision No. 0
November 2017