www.skcltd.com
007-03-004 Issue D
Page 17
Calibration of the chek-mate Flowmeter
Important notes for third party flow calibrations:
1. It is strongly recommended to send a copy of this instruction manual with the chek-mate
unit when sending to a third party calibration laboratory.
2. It is recommended to fit a new battery prior to sending the chek-mate for third party
calibration.
3. The chek-mate indicates air flow in ml/min on model 375-00205 and litre/min on model
375-0550, at the current ambient temperature and atmospheric pressure, therefore the
reference flow measurement must be corrected to these conditions for comparison with
the chek-mate indicated flow reading.
4. The factory flow calibration is performed under vacuum therefore the calibration gas
used is ambient air with relative humidity of 50% ±20% RH. When performing positive
pressure flow calibrations using compressed dry laboratory air or nitrogen gas, the
difference in gas density must be corrected for.
5. When performing flow calibration under vacuum with the chek-mate connected in series
with the reference flow meter the chek-mate should be connected with its inlet port open
to atmosphere.
6. When performing flow calibration under positive pressure with the chek-mate connected
in series with the reference flow meter the chek-mate should be connected with its outlet
port open to atmosphere.