Instrument Operation 5-47
6. To perform a calibration, set the impactor flow to the first flow
calibration point by pressing the corresponding Setpoint button. The
Actual and Classifier cells populate, the Reference cell for that row is
activated, and an onscreen keypad appears.
Note: Typically the calibration is performed from the smallest to the
largest flow setpoint; however the order in which the reference
flow values are recorded is not important.
Figure 5-31
Electrostatic Classifier User Calibration Screen–Impactor Flow Tab
7. Monitor the flow rate shown in the Classifier cell for 10 seconds or until
the flow rate stabilizes. Record the value from the reference flow
device (to two decimal places) in the Reference field using the
onscreen keypad and press ENTER.
8. Repeat steps 6 and 7 for each of the flow setpoints, until you have
entered a valid Reference flow value for each setpoint.
9. When all the data has been added, press the active setpoint button
again to turn the flow off.
10. The Calibrate button becomes active. If you want to recalibrate the
flow rate, press Calibrate. The Classifier column is recalculated
based on the new calibration curve. The Error (%) column indicates
the accuracy of the new calibration curve. An onscreen message tells
you the calibration is complete and has been saved to the impactor.
11. To calibrate another impactor, remove the current impactor and insert
the next impactor. Press the Clear button in between calibrations in
order to clear data from the previous calibration.