RayTek ThermoView Ti30 user manual Imager Reading Error vs Source DS, Typical Emissivity Values

Page 67

Imager Reading Error vs Source D:S

The following example uses the above Typical Reading Error vs. Source D/S graph:

A 5" diameter source (Size = 5) at a Distance of 50" has D/S = 50/5 = 10. According to the above graph the imager would read less than 1% low in temperature (as shown by the dashed line) for this size target.

Typical Emissivity Values

The following tables provide references for estimating emissivity and can be used when the user does not have the means or the time to determine the emissivity value experimentally. Emissivity values shown in the tables are only approximate. Any or all of the following parameters can affect the emissivity of an object:

1.Temperature

2.Angle of measurement

3.Geometry (plane, concave, convex, etc.)

4.Thickness

5.Surface quality (polished, rough, oxidized, sandblasted)

6.Spectral region of measurement

7.Transmissivity (i.e., thin film plastics)

Note These tables are to be used as a guide only, as emissivity changes with temperature,

1:viewing angle, wavelength, target geometry and surface finish.

Note Your ThermoView Ti30 thermal imager measures infrared energy in the 7 – 14 µm

2:range.

July 1, 2003

- 67 -

Version 1.0

i

Tel: (01943) 602001- WWW.ISSLTD.CO.UK - Fax: (01943) 816796

i

Image 67

Contents User’s Manual ThermoView Ti30Contents Qualitative and Quantitative Temperature Measurements Appendix B Infrared Theory Q&A Glossary Warranty Information Customer Service Contact Information Introduction Netd Quick Specifications TableUnpacking Your New Imager First, the Batteries Removing the Battery PackBattery Packs Normal Charge Cycle Charging the Rechargeable Battery PackDocking Station LED Indicators Attaching the Wrist Strap Getting StartedDisplaying Images Turning the Unit OnInformation Screen Normal Mode Keypad Settings and ControlsThermoView Imager Settings Switches icons not shown Laser On/Off Toggle Button ThermoView Imager Settings SwitchesLaser Aperture and Optical Channel JapaneseCentigrade/Fahrenheit Toggle Button LCD Backlight Illumination SwitchPalette Switch Measurement Mode SwitchLevel point Gain and Level ThumbwheelsFocus Wheel Automatic Semi AutomaticLocation of the Focus Wheel TriggerMain Loop Man Machine Interface Flow ChartsImage Recording Procedure Emissivity Adjustment Procedure July 1 Version Recording an Image Quick Image Fix Procedure Array Recalibration ProcedureRetrieving an Image Retrieve ModeDownloading and Looking at Images Installing the SoftwareHooking Up the Docking Station Connecting the Docking Station to Your ComputerConnecting the USB Connector to the USB Port InsideIR Main Screen at Program Launch Sync button Downloading ImagesDownload Data Screen Saving ImagesContents of Images Folder Setting the Imager ClockJuly 1 Version Looking at Your Downloaded Images Field USB PortViewing Thumbnail Images Viewing a Single Image Obtaining the Best Image Importance of FocusingSelecting the Color Palette Selecting the Measurement ModeLevelGain Min Level Gain Max Level Gain Tip Distance to Target Spot Ratio Qualitative and Quantitative Temperature MeasurementsField-of-View Optical DiagramDS ratio D / S = Environmental Conditions Ambient TemperaturesEmissivity Reflected Temperature CompensationReflected Temperature Compensation File Management Organizing Your DataUploading Data to Your ThermoView Ti30 Imager Uploading Data to the ImagerEditing Data Before Upload RTC OFF Single Image Screen Analyzing Your DataScale Limits Sample Image at Original Scale Limits Isotherms Sample Image at Original Isotherm SettingAdditional Image Analysis Tools Temperature Table TabProfile Tab Temperature TableProfile Tab Histogram TabNew Folder Menu BarCelsius ThermoView Imager InfoExit FahrenheitHistogram Export Temperature TableExport Image Create ReportTile Horizontal Copy Profile ChartContents CascadeThermographic Report Reporting Your FindingsAppendix a Technical Reference Imager Accuracy ChartTypical Emissivity Values Imager Reading Error vs Source DSAluminum Unoxidized Ni-Cu Gob Appendix B Infrared Theory Q&A Why use noncontact infrared thermometers?How does IR work? Emissivity How to assure accurate temperature measurement?Field-of-view Distance to spot ratioWhat are the most popular applications? How to take temperature measurement?Glossary Calibration Source Background TemperatureBlackbody CalibrationFar Field Display ResolutionDrift EMI/RFI NoiseGray Body Focus Point or DistanceFull Scale Full Scale AccuracyMinimum spot size LaserLoop Micron or µmPyroelectric Detector Optical ResolutionNon-Gray Body Optical PyrometerRepeatability Reflected Temperature CompensationResolution Relative HumiditySpectral Response Storage Temperature RangeTemperature Temperature Coefficient or Ambient DeratingTransfer Standard Temperature ResolutionThermal Shock Time Constant