Vaisala GMK220 - Manual (Page 5)

Chapter 2______________________________________________________________Product description
VAISALA _____________________________________________________________________________3
CHAPTER 2
PRODUCT DESCRIPTION
Introduction
Although Vaisala's CO
2
instruments are inherently stable, periodical
checkings should be performed according to the recommendations
given in the relevant user's guide. The GMK220 calibrator (Figure 1)
is intended for spot checking and two-point calibration of the carbon
dioxide probes GMP221 and GMP222, which currently are used in
Vaisala's GMT220 and GMM220 series CO
2
transmitters.
GMK220 can be used for
•
spot checking with one reference gas
•
two-point calibration with two reference gases
Spot checking can be carried out when there is a need to check if the
probe is operating correctly. If adjustement is needed, two-point
calibration shall be carried out.
GMK220 needs only the probes
For checking and calibration, the GMK220 needs only the probes, not
the whole transmitter. The GMK220 calibrator calibrates and stores
the calibration parameters to the non-volatile memory in the probes.
This enables true interchangeability of the probes and forms a good
basis for the continuous measurements with good traceability.
NOTE The GMK220 can be used to calibrate the probes marked with a little
star (*) in the probe label. A little star indicates that the probe has the
program version compatible with the calibrator.