8 9
5-5.Focus
• To adjust focus, clockwise or Anti-clockwise rotates the IR Lens.
• When target comes into focus, it shows a sharper image.
• When the target moves out of focus, the thermal image becomes blurry.
Note: Correct focus is important in all imaging applications. Correct focus makes sure that the infrared
energy is correctly directed onto the pixels of the detector. Without the correct focus, the thermal image
can be blurry and the radiometric data will be inaccurate. Out-of-focus infrared images are frequently
unusable or of little value.
5-6.Shutter
• The thermal image of the Thermal lmager becomes blurry, when the Thermal Imager no correcting after
some minutes or the Thermal Imager changes target.
• To get fine thermal image, the Thermal Imager need to correct.
• The Thermal lmager has two mode for correcting. Manual and Auto mode.
• In Manual Mode, long press the down arrow button, the Thermal Imager will correct.
• In Auto Mode, the Thermal Imager can correct automatically white The thermal image of the Thermal
lmager becomes blurry.
5-7.Temperature Measurement
• All objects radiate infrared energy.
• The quantity of energy radiated is base on the actual surface temperature and the surface emissivity of
the object.
• The Thermal Imager senses the infrared energy from the surface of the object and uses this data to
calculate an estimated temperature value.
• Many common objects and materials such as painted metal, wood, water, skin, and cloth are very good
at radiating energy and it is easy to get relatively accurate measurements.
• For surfaces that are good at radiating energy (high emissivity), the emissivity factor is >0.90.
• This simplification does not work on shiny surfaces or unpainted metals as they have an emissivity of
<0.6, These materials are not good at radiating energy and are classified as low emissivity.
• To more accurately measure materials with a low emissivity, an emissivity correction is necessary.
• Adjustment to the emissivity setting will usually allow the Thermal Imager to calculate a more accurate
estimate of the actual temperature.
• More information please see Emissivity Adjustment to get the most accurate temperature measurements.
Operating Instruction for Thermal Imager / English
Operating Instruction for Thermal Imager / English
Focus to get
clear image
5-8. Emissivity Adjustment
• The correct emissivity value is important to make the most accurate temperature measurement.
• Emissivity of a surface can have a large effect on the apparent temperatures that the Thermal Imager
observes.
• Understanding the emissivity of the surface, but may not always, allow you to obtain more accurate
temperature measurements.
Note: Surfaces with an emissivity of <0.60 make reliable and consistent determination of actual
temperature problematic. The lower the emissivity, the more potential error is associated with the
Imager’s temperature measurement calculations. This is also true even when adjustments to the
emissivity and reflected background adjustments are performed properly.
• Emissivity is set directly as a value or from a list of emissivity values for some common materials. The
global emissivity displays in LCD Screen as E=x.xx.
• The following table gives typical emissivity of important materials.
Material Emissivity
Water 0.96
Stainless steel 0.14
Aluminum plate 0.09
Asphalt 0.96
Concrete 0.97
Cast iron 0.81
Rubber 0.95
Wood 0.85
Brick 0.75
5-9.Reflected Temperature
• Using the offset factor, the reflection is calculated out due to the low emissivity and the accuracy of the
temperature measurement with infrared instruments is improved.
• In most cases, the reflected temperature is identical to the ambient air temperature.
• Only when objects with strong emissions with much higher temperature are in the proximity of the object
being measured should be determined and used.
• The reflected temperature has only little effect on objects with high emissivity.
• The reflected temperature can be set individually.
• Follow these steps to get the right value for the reflected temperature.
1. Set the emissivity to 1.0.
2. Adjust the optical lens to near focus.
3. Looking in the opposite direction away from the object, take a measurement and freeze the image.
4. Determine the average value of the image and use that value for your input of reflected temperature.
Tape 0.96
Brass plate 0.06
Human skin 0.98
PVC plastic 0.93
Polycarbonate 0.80
Oxidized copper 0.78
Rust 0.80
Paint 0.90
Soil 0.93
