3M 48N user manual Sensors, Globe Thermometer, Waterless Wetbulb & Relative Humidity Sensor

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Sensors

Sensors

 

Globe Thermometer

 

Sensors

Globe Thermometer

The globe thermometer (left position) gives an indication of the radiant heat exposure on an individual due to either direct sunlight or hot objects in the environment. This is accomplished by placing a temperature sensor inside a blackened copper sphere and measuring the temperature rise. The WBGT index is based on the response of a 6 inch diameter globe. The QUESTemp uses a 2 inch diameter globe for a faster response time. The temperature of the 2 inch globe is correlated to match that of a 6 inch globe.

Waterless Wetbulb & Relative Humidity Sensor

The relative humidity sensor (middle position) is used to calculate the Waterless Wetbulb from a combination of dry bulb temperature, humidity and wind speed measurements. The waterless wetbulb is used to calculate an estimated WBGT value.

Dry Bulb Thermometer

The dry bulb thermometer (right position) measures the ambient air temperature. This measurement is used in the outdoor WBGT calculation when a high solar radiant heat load may be present. The series of white plates surrounding the sensor shield it from radiant heat.

A B C

A. Globe thermometer

B. Relative humidity sensor

C. Dry bulb thermometer

Figure 1-8: Sensors identified

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Contents Market Leader Contents List of Figures Iii Introduction QUESTempº 48N ModelUp and Running overview Getting StartedPlacing the QUESTempº 48N on the job site Keypad Operation Keys ExplanationTurning on, logging/capture an event, and turning off Index start-up screenIndicator arrow ∙ Numeric counterWaterless Wetbulb & Relative Humidity Sensor SensorsGlobe Thermometer Dry Bulb ThermometerWetBulb Globe Temperature Wbgt Stay Times/Rest Times IndiciesOperating QUESTempº 48N SetupSettings Explanation View Selecting Setup parameters 11 Selecting temperature setting and setupPrint ResetRun Following measurements can be accessed on the display Displayed Items19 Battery & memory screen Screen 6 Index Stay Time/IndexData Logging 22 Navy PHELs screenElectronic sensor check Performing an electronic sensor checkSensor Alignment RH Sensor AlignmentLow RH Alignment screen Adjust % to 33% using up/down arrow 27 RH alignment with Low % examplePrinting Data/CommunicationsParallel 30 Sample printoutsApproved 9-Volt Batteries PoweringVolt Alkaline Battery Replacement Duracell MN1604Appendix a Specifications MeasurementsWeight QUESTemp 48N Block Model LCDHeavy Very Heavy TLV Work and recovery LightAppendix B Heat Exposure Tables Heavy Very Heavy Action LimitUnited States Navy Acgih Clothing CorrectionsPhel Curves Total Exposure Time in Hours Minutes United States Navy Flag Degrees F Flag Conditions for U.S. Navy/Marine Corp. AshoreFlag Degrees C Appendix C Accessories sold separately QT3X-BCCommunicating and Downloading in DMS Appendix D SoftwareDMS quick overview PortData Finder and quick reports 34 Communicating with the QT⁰ 48N and DMSQuick Report select 36 Quick ReportCalibration Customer serviceWarranty Contacting 3M InstrumentationAbout Us