11066 Searchpoint Optima Plus v2.indd - Merkantile

MAN0551.P65 Issue 06 - 03/042108M05015. COMMISSIONINGProvided the displayed gas reading falls within the +/-5%LEL test tolerance range, the functional gas test hasbeen completed satisfactorily.44CAUTIONIf the displayed gas reading is not as expected, do notproceed to re-calibrate the unit immediately. Instead,double check the unit’s zero, the test gas and the gassingtechnique. (IR gas detectors do not exhibit significant spandrift and in most instances, any problem will be with thezero or the test gas / technique.) Only consider recalibratinga unit when certain that the zero, test gas andtechnique are correct and that the unit’s gas response issignificantly out. The calibration technique is detailed inSection 6.3.5.2.3 System Level Testing (SHC-1 & Multimeter)Confirmation of correct operation of the complete gas detectionsystem can be done using either test gas at the requiredconcentrations (Option B) or by FORCEing the unit’s 4-20mAoutput under control of the SHC-1 interrogator (Option A):-CAUTIONWhen performing system level tests, ensure that anyresulting alarms or executive actions will not give rise tounintended emergency drills or loss of production / shutdown.Note: It is assumed that the control system has been set upfor currents of 4mA and 20mA to read 0.0% LEL and100% LEL respectively. If necessary, the FORCE 4-20mA option can be used for setting up the control card.Be aware that a 10 minute timeout applies to FORCE’d4-20mA outputs.