The definition of infrared thermal imager emissivity is refers to the object surface emissivity radiation energy and the ratio of the same temperature of blackbody radiation energy.
Is a kind of ideal blackbody radiator, it absorbs all the wavelengths of the radiation energy, no energy reflection and through its surface emissivity is 1.
All kinds of material emissivity is determined by the material object itself, under the same temperature, the material is different, outward radiation energy will also be different.
Below, for example, we can see that three points is the surface of the cup at the same time, but due to the surface of the material is different, the radiation energy, temperature with infrared thermal imager fluke see instructions are quite different.
Fluke infrared thermal imager emissivity method for determining the emissivity of the measured material has four kinds of methods to determine: 1 refer to various materials emission rate to determine;
2 will be a piece of electrical tape (
Stick on surface to be tested, and then by adjusting the infrared thermal imager emissivity, the measured temperature and with insulation tape on the surface of the material surface temperature in the same or close to, the emissivity is the material being tested right emissivity of the object;
3 the painting (
Uniform coating in the surface of object to be tested, and then by adjusting the infrared thermal imager emissivity, until there is no paint in the surface temperature and spray paint surface temperature of the same or close to, the emissivity is the correct destination object emissivity;
4 use non-contact thermometer, such as thermocouple, heat resistance, such as measuring surface temperature, and then by adjusting the infrared thermal imager emissivity, until the surface temperature measured by a thermal imager and contact contact thermometer measured the surface temperature of the same or close to, the emissivity is the correct destination object emissivity.
Infrared thermal imager emission rate to determine the materials used in method one: consult material emission rate, emission rate in the product of form a complete set of various materials, can query to the manual;
Method 2: put insulating tape (
Electrical insulating tape, 3 m brand 1712, any color)
, the emissivity of insulating tape is: 0.
Method 3: spraying of acrylic resin (
Botny automatic spray paint, any color)
, this kind of paint emissivity is: 0.
The diagram below?
Method 4: the contact thermometer used for Fluke 566, or Fluke17B multimeter.
Below: the use of the method for determining the occasion the first method are provided for reference only;
The second method is suitable for the target to be measured is relatively large, low temperature (
Less than 80 ℃)
After to test without changing the original target surface condition, such as manufacturing, such as all kinds of heat dissipation module, bright and clean chips (
Surface of the metal surface, etc. ;
The third method can be applied to higher temperature target, also can use the small size of target, but can accept the measured object surface condition was changed, such as pipe, valves, equipment maintenance situations stated equipment;
Manufacturing, the smaller the chip surface, pin, irregular heat sink, the top of the capacitor, LED chip (
Silver plated surface)
And so on;
The fourth kind of method is suitable for the measured target allow surface contact temperature measurement occasions.
Operation notice the first method: only for reference, not accurate temperature measurement;
The second method: try to make the tape close contact with the surface of the measured target, no air bubbles or the phenomenon such as fold, need to set aside more than 5 minutes of time, make the measured target surface and the adhesive tape fully reach thermal equilibrium state;
The third method: try to make the paint surface evenly, and thin,
But to cover the target surface to be tested)
, at the same time, to give the customer specification, target may leave a residue after spraying;
Suggest users spraying after 3 minutes, and then to test;
Fourth method: should make thermocouple and target being measured surface contact is good, also asked that the test data must be after the temperature stability data.