RKI Instruments GX-3R Pro Operator's Manual page 2

WARNING
Read and understand this instruction manual before operating instrument.
Improper use of the gas monitor could result in bodily harm or death.
Maintenance of the gas monitor is essential for proper operation and correct
readings.
Bump test the instrument before each day's use with a known concentration of
each target gas. A bump test can be done in User Mode's BUMP TEST item or
by applying gas in Measuring Mode. The instrument does not need to be
calibrated unless it does not pass the User Mode bump test or does not respond
appropriately, as defined by the user, in Measuring Mode. For more
information about bump test and calibration requirements, see IEC 60079-29-
2.
GX-3R Pro Operator's Manual