Page 16
007-03-004 Issue D
www.skcltd.com
Calibration Interval
SKC recommend a minimum calibration interval of one year for this product. However, it is
the responsibility of the user to determine the most suitable interval in order to meet their
quality assurance system requirements. Consideration should also be given to the frequency
of use and operating environment when determining the calibration interval.
Calibration Method
The chek-mate is primarily designed to perform flow calibration of air sample trains which
incorporate an air sample pump to provide the airflow, therefore the airflow is pulled through
the chek-mate by the vacuum generated by the air sample pump.
To ensure that the SKC factory flow calibration is representative of how the chek-mate
is actually used the flow calibration is performed under vacuum. Factory calibrations are
performed by applying the airflow alternately to the chek-mate and reference flowmeters.
SKC recommend that subsequent flow calibrations of the chek-mate flowmeter are also
performed under vacuum and applying the airflow alternately to the chek-mate and reference
flowmeters. However, positive pressure flow calibration using compressed laboratory air or
nitrogen gas is also acceptable, and series connection of the chek-mate and reference
flowmeters under either vacuum or positive pressure are also acceptable.
Calibration of the chek-mate Flowmeter