General Monitors S4000CH, Руководство пользователя

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Model S4000CH
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If the S4000CH is placed in the Calibration Mode and no gas is applied for six minutes,
the unit will revert to a Fault condition. Re-applying the magnet over the GM logo will
return the unit to operational mode with the previous calibration values unchanged.
3.14.3 Adjustable Calibration Level
The S4000CH provides the user with the ability to adjust the calibration level from 25%
LEL to 90% LEL. The default value from the factory is 50% LEL. This allows the user to
utilize gas already available at their installation, or to perform cross-calibration to a similar
gas. Adjusting the Calibration Level is performed in Setup Mode.
NOTE:
%LEL to %Volume fraction is converted by using NFPA 325 Guide to Fire Hazard
Properties of Flammable Liquids, Gases, and Volatile Solids. For example, 100%
LEL CH
4
is shown in NFPA to be 5% Volume, Calibration is at 50% LEL or 2.5%
Volume.
3.14.4 Remaining Sensor Life
The S4000CH Intelligent Sensor provides an estimate of remaining sensor life, in percent
remaining, to provide the user with an early warning of the need for sensor replacement.
The remaining sensor life is updated each time the unit is calibrated. The current
remaining sensor life estimate is displayed during the zeroing portion of a calibration
sequence. It can also be read via the Modbus and HART interface (Section 6.8.22).
NOTE:
Remaining sensor life is an estimate of sensor degradation derived from sensor
sensitivity. Because sensor sensitivity is affected by factors other than the natural
sensor degradation, users must establish their own reference by resetting sensor
life whenever these factors are at play. Some examples of these factors are new
sensor installations, sensor replacement, change of the target gas, and changes
in the access of gas to the sensor (produced by the TGA, RGC, or splash guard).
If sensor life is not reset, the remaining sensor life indicator will no longer reflect
the true state of the sensor.
3.14.5 Initializing the Remaining Sensor Life
The remaining sensor life estimate must be initialized each time a new hydrocarbon
sensor is installed. The initialization should be done during the first calibration of a newly
installed sensor. After the sensor has been on power for a minimum of one hour, enter
calibration mode as described in Section 3.14.1. While the display is flashing the
remaining sensor life estimate during zeroing, apply the magnet to the GM logo on the
cover. The flashing number will change to “
100
”, indicating the sensor has 100% of
remaining sensor life. Complete the calibration per Section 3.14.1.
3.15 Calibration Equipment
3.15.1 Portable Purge Calibrator
The portable purge calibrator is a compact, accurate and safe system containing a non-
explosive gas concentration. The lecture bottle is filled with a standard 50% LEL mixture
of gas/air. Using a known gas/air mixture reduces the likelihood of error in field calibration.
The hose and cup adapter allow for quick calibrations and gas checks. Pre-mixed
calibration gases at 50% LEL are available in lecture bottles at 1200 psia, 8.3 MPa
maximum pressure.