Bacharach H25-IR manual Improving PPM Measurement Accuracy using the CAL Factor

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Calibration

H25-IR

 

 

7.Compute the new CAL Factor by dividing the actual leak rate of the external leak source by the reading recorded in Step 6. For example, if the leak rate of the external leak source is 0.4 oz/yr and the measured rate was 0.43 oz/yr, then the new CAL Factor is 0.4 ⎟ 0.43 = 0.930.

This new CAL Factor establishes the relationship between the internal calibration gas and the gas type selected to be measured.

8.Enter the new CAL Factor as described in Section 3.4.3 Adjusting the CAL Factor. Note that the displayed Gas Type should match the gas selected in Step 2.

9.From this point on the operator can perform an internal calibration and get accurate measurements for other gas types using whatever gas is contained in the internal leak source.

3.4.2 Improving PPM Measurement Accuracy using the CAL Factor

The CAL Factor can be adjusted to improve the accuracy of the ppm measurement by calibrating the instrument on the gas being measured. The accuracy of the ppm measurement after performing this procedure will equal the accuracy of the gas sample, ±1%. Note that the accuracy of the instrument’s ppm measurement depends on the accuracy of the gas sample.

The new CAL Factor is determined by sampling a known dilution of gas whose accuracy is better than the ppm measurement accuracy as stated in Section 7 Specifications. The concentration of the sample must also be corrected for ambient temperature and pressure at the time of calibration. A minimum sample size of 5 liters is required.

Calibration is best performed at or near full scale, it can however, be done at any concentration and ideally in the range where maximum accuracy is desired down to, but not below, 100 ppm.

The instrument should be operating for at least 30 minutes prior to performing a calibration.

Verify that the current CAL Factor is set to 1.000 by selecting the Main Menu > CAL DATA > CAL FACTOR function. If necessary, reset the CAL Factor to 1.000. Refer to Section 3.4.3 Adjusting the CAL Factor.

With the instrument operating in its ppm measurement mode (refer to Section 4.2.8 Measuring the PPM Level), insert the probe tip into the gas-sample bag and allow the instrument to sample until the ppm reading on the display is stable. At this time record the ppm reading. The new CAL Factor is computed by dividing the known gas concentration value by the measured value. Typically this number will be between 0.95 and 1.05. Enter the new CAL Factor as described in Section 3.4.3 Adjusting the CAL Factor.

IMPORTANT! If the instrument is switched back to measuring the leak-rate, then the instrument must be recalibrated on the gas being measured.

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Instruction 3015-4342

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Contents H25-IR Infrared Refrigerant Gas Leak DetectorWarranty Register Your Warranty by VisitingTable of Contents Parts and Service AC Power and Grounding Safety PrecautionsHazard Symbols IntroductionWorking Inside the Instrument CleaningExplosive Atmosphere Misuse and Modifications to Instrument Case of MalfunctionOrdering Information Unpacking and Initial ChecksFeatures and Capabilities Functional Overview Leak Rate = Flow Rate x Gas ConcentrationNames and Functions of Components Front ViewRear View Interior Standard Probe Standard Probe with LED and Programmable PushbuttonSmart Probe Smart Probe Keylock Function Menu System System MenuPreparing for Operation Connecting the ProbeConnecting the AC Power Cord Turning on the InstrumentGas Type System SetupMain Menu System Setup Menu Leak UnitsRelays 4 4-20 mA LoopBrightness Pchk ModeReset Defaults ClockConfiguring the Setups Function Setup NameRange Feedback Mode SetpointCalibration Search Auto ZeroTypical Relay 1 Wiring External Relay ConnectionsMA Current Loop Connector 4-40 mA Current Loop ConnectionPreparing for Operation H25-IR Internal Calibration Selection CalibrationSelecting Internal or External Calibration Calibration Data MenuExternal Calibration Selection and Setup CAL Internal CalibrationExternal Calibration Procedure CAL FactorMaterial Required Improving PPM Measurement Accuracy using the CAL Factor Adjusting the CAL Factor Restoring Factory CalibrationCalibration H25-IR Initial Setup Using the H25-IRPower OperationSetup Selection Range SelectionVolume Adjustment Searching for a LeakMeasuring the Leak Rate Measuring the PPM LevelLogging Measured Readings Working with Logged MeasurementsLog Menu Clearing the Log Diagnostics Menu What to Do when a Fault OccursWhat is PCHK? RS-232 CommunicationOperation H25-IR Maintenance Diagnostics MenuSensor Data Last Fault Pressure Factory MenuIR Emitter Factory Factory MenuLeak Gas Auto GainLeak Rate Leak TempLeak Tempco Sensor CalModel Select Probe TypeFirmware Flashing Memory Items RequiredSelect Setup Communications Select File Load Flash Image Part Replacement Removing the Top CoverFuse Replacement Probe Tip Filter & O-Ring ReplacementInternal Filter Replacement Parts and Service Replacement PartsService Centers United StatesSpecifications CFCs, HCFCs, HFCs and HalogensSpecifications H25-IR Appendix a Factory Defaults ContinuousAppendix a H25-IR H25-IR Appendix a Headquarters Hunt Valley Circle, New Kensington, PA
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