Calibration, Flow rate and volume display, Verifying flow rate using a primary standard – SKC 210-2000 AirChek 2000 User Manual

Page 20

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17

Flow Rate and Volume Display

Flow rate displayed on the pump LCD is the fl ow to which the
pump has been calibrated. To maintain fl ow as displayed, the
pump automatically adjusts fl ow during sampling for changes
in temperature and atmospheric pressure that may diff er from
the temperature and atmospheric pressure present at the time
of calibration. The fl ow rate display does not change from
the calibrated fl ow rate. The pump will fault if it is unable to
maintain the calibrated fl ow rate.

Volume displayed on the pump LCD is ”corrected” in that it
is the result of a continual calculation of corrected fl ow rate
multiplied by sample time.

Verifying Flow Rate Using a Primary Standard

Use this calibration method for low fl ow calibration or if not using CalChek.

1. Ensure pump has run for fi ve minutes before calibrating.
2. Using 1/4-inch Tygon

®

tubing, connect the pump inlet to the outlet of

the representative sampling medium using fl exible tubing.

To ensure sample integrity, tubing seals tightly onto the pump inlet
fi lter cover. Use care when removing tubing to prevent cracking or
breakage of the inlet fi lter cover.

3. Connect the inlet of the sampling medium to a primary standard

calibrator using another length of fl exible tubing.

4. From HOLD, press [] to run the pump and enter  within 10

seconds. You are in User Interface Level One. SET fl ashes on the LCD.

5. The LCD will display a fl ashing fl ow rate from the last sample taken. If

you do not wish to change the fl ow rate go to Step 6.

6. Press

 to increase the fl ow rate or  to decrease the fl ow rate to the

desired sett ing.

7. Press

. The fl ashing ADJ appears on the LCD, replacing the fl ashing

SET. The pump fl ow rate can now be calibrated using a primary
standard calibrator.

The fl ow rate displayed on the calibrator will change as a result of
this adjustment, not the fl ow rate displayed on the pump. The pump
will display an adjustment factor (ADJ) only.

8. Compare

the

fl ow rate from the calibrator to that displayed by the

pump. If the calibrator indicates a higher fl ow rate than the pump, press
 until the pump and calibrator are in agreement (within 10 ml). If the
calibrator indicates a lower fl ow rate than the pump, press  until the
pump and calibrator are in agreement (within 10 ml).

Calibration

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