Pmt Adjustment; Figure 5 Flow Calibration Screen - Teledyne T640 Standard Operating Procedure

5. Wait at least one minute for the flow to re-stabilize.
6. Press the value button next to the "Actual Flow" field, enter the value measured by the Flow
Standard, and press the "Calibrate" button on this screen. The Status should change to
"Success".
The Measured Flow value should change to closely match the Actual Flow within a few
seconds.

10.2.3 PMT Adjustment

The Particle Sensor PMT Calibration uses SpanDust™, a monodisperse dust with a specific
refractive index. All T640 instrument PMTs have a very specific response to this span dust
which allows for the sensor to be adjusted in the field for drift caused by contamination of the
optics. This is not a calibration of the optical sensor based on the mass of dust being used, but
simply a mechanism to Adjust the PMT response to particles with a specific and known
refractive index.
For this procedure, ensure channels 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.

Figure 5 Flow Calibration Screen

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DEP 03-21
Revision No. 0
November 2017