RKI Instruments M2 Rig Monitor - Manual (Page 33)

M2 Rig Monitor Operator’s Manual 28
Calibration Frequency
Although there is no particular calibration frequency that is correct for all applications, a
calibration frequency of every 3 to 6 months is adequate for most Rig Monitor
applications. Unless experience in a particular application dictates otherwise, RKI
Instruments, Inc. recommends a calibration frequency of every 3 months.
If an application is not very demanding, for example detection in a clean, temperature
controlled environment where H
2
S is not normally present, and calibration adjustments
are minimal at calibration, then a calibration frequency of every 6 months is adequate.
If an application is very demanding, for example if H
2
S is present often and in significant
concentrations or the environment is not well controlled, then more frequent calibration
than every 3 months may be necessary.
Calibration
This section describes how to calibrate the M2 Rig Monitor. It includes procedures to
prepare for calibration, enter Calibration Mode, adjust the fresh air (zero) setting, adjust
the span setting, and return to normal operation.
WARNING: The M2 Rig Monitor is not an active gas monitoring device during the
calibration procedure. The 4-20 mA output signal will “freeze” at 3.5 mA
and all relays will remain in their non-alarm state while the M2 Rig
Monitor is in Calibration Mode. The output signal will not indicate
current readings and the relays will not resume operating normally until
the M2 Rig Monitor is in normal operation again.
Non-Intrusive Calibration
If non-intrusive calibration is required, follow the instructions below, but do not remove
the junction box cover. Use the magnetic wand accessory to actuate the magnetic switches
instead of pushing the control switch buttons. To actuate a magnetic switch and perform
the same operation as pressing a control switch button, touch the magnet in the end of the
magnetic wand to the Rig Monitor’s glass cover directly above the magnetic switch you
wish to actuate. Touching the glass and removing the wand is the same as pressing and
releasing a button. Touching the glass and keeping the wand in place is the same as
pressing and holding a button.
Calibration Gas Response Memory Feature
The Rig Monitor has the capability to “remember” the detector’s response to the
calibration gas after the gas is removed from the detector during the fresh air and span
adjustment procedure. This feature enables one person to perform calibration if the
detector is mounted remotely from the Rig Monitor. When zero air is applied to the H
2
S
detector during a fresh air adjustment, the Rig Monitor will freeze the display reading at
the lowest response and the Rig Monitor will continue to display this reading and retain it
in its memory until the fresh air adjustment procedure is completed. When calibration gas
is applied to the H
2
S detector during a span adjustment, the Rig Monitor will freeze the
display reading at the highest response to the calibration gas. The calibration gas can then
be removed and the Rig Monitor will continue to display this reading and retain it in its
memory until the span adjustment procedure is completed.