3M 48N user manual WetBulb Globe Temperature Wbgt, Stay Times/Rest Times Indicies

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Measurements

Measurements

WetBulb Globe Temperature (WBGT)

Measurements

The QUESTemp° 48N data logging, with an event logging mode, heat stress monitor directly senses three parameters: dry bulb temperature (DB), globe temperature (G), and relative humidity (RH).

It computes the Wet Bulb (WB), the Wet Bulb Globe Temperature (WBGT), and the Stay Times Indices for ACGIH, U.S. Navy PHEL charts, and Flag Conditions for U.S. Navy/Marine Corp. Ashore.

WetBulb Globe Temperature (WBGT)

The WBGT is a type of temperature index which combines the effects of temperature, humidity, radiant heat, and air flow and provides a relatively simplistic tool to analyze thermal comfort. The resulting WBGT values can then be compared to indices of work-rest regimens (stay times) based upon workloads.

The WBGT calculation is a weighted average of the three temperature sensors using the following formulas:

**NOTE: Navy and Marine calculations are all based on the outdoor computation.

WBGT (outdoor) = 0.7WB + 0.2G + 0.1DB (denoted as “WBGT” on the display)

Stay Times/Rest Times (Indicies)

Stay Times Indices represent how long a worker should be able to safely work under heat stress conditions. Select one of four indices for displaying and printing from the unit: ACGIH Stay Times, NAVY PHEL’s, or Flag Conditions for U.S. Navy/Marine Corp. Ashore. Refer to Appendix B for more information on the indices. NOTE: it will appear as “Index” on the measurement screen.

Remote measurements

The top sensor bar may be removed from the instrument and used through a remote cable. (Please refer to Appendix C for remote cable options.) Shelter the instrument and remote the sensor bar if the measured environment is expecting heavy rain or if temperatures are above 60°C.

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Contents Market Leader Contents List of Figures Iii QUESTempº 48N Model IntroductionPlacing the QUESTempº 48N on the job site Getting StartedUp and Running overview Keys Explanation Keypad OperationIndex start-up screen Turning on, logging/capture an event, and turning off∙ Numeric counter Indicator arrowDry Bulb Thermometer SensorsGlobe Thermometer Waterless Wetbulb & Relative Humidity SensorStay Times/Rest Times Indicies WetBulb Globe Temperature WbgtView SetupSettings Explanation Operating QUESTempº 48N11 Selecting temperature setting and setup  Selecting Setup parametersRun ResetPrint Displayed Items Following measurements can be accessed on the displayStay Time/Index 19 Battery & memory screen Screen 6 Index22 Navy PHELs screen Data LoggingPerforming an electronic sensor check Electronic sensor checkRH Sensor Alignment Sensor Alignment27 RH alignment with Low % example Low RH Alignment screen Adjust % to 33% using up/down arrowData/Communications Printing30 Sample printouts ParallelDuracell MN1604 PoweringVolt Alkaline Battery Replacement Approved 9-Volt BatteriesMeasurements Appendix a SpecificationsWeight LCD QUESTemp 48N Block ModelHeavy Very Heavy Action Limit Work and recovery LightAppendix B Heat Exposure Tables Heavy Very Heavy TLVPhel Curves Total Exposure Time in Hours Minutes Acgih Clothing CorrectionsUnited States Navy United States Navy Flag Degrees C Flag Conditions for U.S. Navy/Marine Corp. AshoreFlag Degrees F QT3X-BC Appendix C Accessories sold separatelyPort Appendix D SoftwareDMS quick overview Communicating and Downloading in DMS34 Communicating with the QT⁰ 48N and DMS Data Finder and quick reports36 Quick Report Quick Report selectContacting 3M Instrumentation Customer serviceWarranty CalibrationAbout Us