Omega Engineering OS524, OS530HR, OS531, OS53X-CF, OS533, OS532, OS530L, OS523 Calculating Temperature

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Appendix: How Infrared Thermometry Works A

Wien’s Displacement Law describes the exact mathematical relationship between the temperature of a blackbody and the wavelength of the maximum intensity radiation.

λm = 2.898

T

where λm = wavelength measured in microns T = temperature in Kelvin

Calculating Temperature

The net thermal power radiated by an object has been shown to depend on its emissivity, its temperature and that of the ambient temperature around the object. A very useful equation known today as the Stefan-Boltzmann Law has been shown both theoretically and empirically to describe the relationship.

I = thermal power in watts/meter2

ε= Emissivity

σ= 5.6703 x 10-8watts/meter2 x K4 (Stefan’s constant) T = temperature of object in Kelvin

Ta = temperature of ambient surroundings in Kelvin

The infrared thermometer uses this equation directly in calculating the temperature of an object. The incident power is measured by the infrared detector. The emissivity of the object is determined by the user. The ambient temperature is measured by a sensor inside the thermometer. With all quantities known, the thermometer uses the Stefan-Bolzmann Law to calculate and output the temperature of the object.

A-3

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Contents User’s Guide Servicing North America For immediate technical or application assistanceServicing Europe Unpacking Instructions Model No Description Page Unpacking Instructions Chapter General Description Contents General Description Introduction Features OS531 OS532 OS533 OS534 OS530HR OS530L-CF Features OS523 OS524 Parts of the Thermometer Front of the ThermometerDisplay Details Key Rear of the Thermometer OS530 Series Handheld Infrared Thermometer Rear ViewGeneral Description Battery Operation Ac Power OperationOperating the Thermometer OS530/OS520 Series with Built-in Laser SightingField of View OS531, OS532, OS530L Field of View OS534, OS523-1 Field of View OS523-2 10 Field of View OS524 Measurement Techniques Trigger11 Recorder Hookup Real Time Mode Active Operation If the trigger is pulled two times in rapid sequenceRecall Mode 13. Visual Function Flow Chart Adjusting Emissivity Using the Lock FunctionCalculating Temperature Values Changing the Temperature from F to C or vice versaTurning on the Display Backlighting Thermocouple Input OS532, OS533, OS534 Using the Alarm Functions If you are not in High Alarm Display Mode HAL whenTo set the low alarm value OS533, OS534, OS523, OS524 To disable this mode, press the key again Icon disappears One Stop Bit Key to decrement the printing interval. System Requirements Irtempsoft Connecting the IR-System to the PC Using the Handheld Infrared Thermometer Storing the Temperature Data on Command OS534, OS523, OS524 Erasing the Temperature Data from Memory Recall Mode Passive Operation ModeFunctional Flow Chart Recall Mode AMB temperature MEM location Reviewing the Last ParametersPRN F Using the Handheld Infrared Thermometer Laser Sighting Description Rear ViewOperating the Laser Sighting Laser DotLines of Sight of the Laser Sighting and Thermometer Installing and Operating the Sighting Scope Sighting ScopeInstalling the Sighting Scope Safety Warning Maintenance Replacing the BatteriesCleaning the Lens Calibrating the ThermometerServicing the Laser Sighting Troubleshooting Guide Problem SolutionProblem If you see an error code, either Target are offset by design Specifications are for all models except where noted SpecificationsOS533, OS534, OS523, OS524 No Laser Sighting 17 hours continuous Laser Sighting Glossary of Key Strokes Glossary of Key Strokes Thermal Radiation Appendix How Infrared Thermometry Works aBlackbody Calculating Temperature Optics Field of View Metals Appendix Emissivity ValuesNonmetals Material Emissivity εAppendix Determining an Unknown Emissivity Figure C-1. Determining Emissivity Figure C-2. Determining Emissivity with a Drilled Hole Appendix Determining an Unknown Emissivity Index Field of View Diagrams Recall WARRANTY/DISCLAIMER Shop online at omega.com PH/CONDUCTIVITY