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Infrared-Temperature is a manufacturer of Temperature Measurement Equipments, Infrared Thermometers,
Infrared Sensor & IR Sensor. |
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Frequently Asked Questions &
Infrared Tutorial
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Infrared Tutorial
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Infrared
History
What is infrared?
Why can't I see infra red?
What kind of theory & technology is involved
in infrared thermometers?
Infrared - how it works |
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Infrared FAQs
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Is
accuracy compromised because these IRT's are so small?
Can infrared thermometers measure air temperature?
Can I measure the body temperature of an Ant by
Infrared Measurement Technology?
How far?
Can the infrared thermometer operate in complete
darkness?
Can the infrared thermometer penetrate
a building, measure what's inside?
Now can I measure the body temperature of a fish in
my aquarium?
How do I know, my infrared thermometer is
still accurate?
Hint to get accurate reading with infrared
thermometer?
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Infrared Tutorial
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What is the history of infrared temperature measurement?
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The Royal Astronomer Sir
William Herschel discovered "Dark Heat" radiation in 1800.
In 1880 the term "infrared" was coined. Samuel Langley
invented the bolometer that measures variations of resistance when
heated.
In 1901 a bolometer could detect a cow at 400 meters.
After World War II, many countries invested huge amounts of money in
IR for military applications.
In 2002 Radiant Innovation Incorporated designed the most compact
and the most affordable IR thermometer (IRT). Low cost IR
thermometers are achieved by using proprietary ASIC System on a Chip
(SoC) technology incorporating MEMS-based advanced thermal sensors.
This advanced low-power design also resulted in the longest battery
life or any available IR thermometer (70hours continuous use). |
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What is infra red?
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| Infra red just like any light
ray, is an Electromagnetic Radiation, with lower frequency (or
longer wavelength) |
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| Anything material above
absolute zero (-273.15 degrees Celsius or 0 Kelvin), radiates in the
infrared. Even ice emits infrared radiation. |
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Why can't I see infrared?
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| Human eyes are design for
visible light, but two species are known to detect IR: some rattle
snakes and beetles. Even though IR is not visible to the human eye,
your skin can sense IR. When beside a campfire, you can feel the
warmth of heat radiated from the fire. |
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What kind of theory & technology is involved in an IR
Thermometer?
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Quantum physics is the key
theory: the total radiation energy is proportional to the fourth
power of the absolute temperature (Stefan-Boltzmann Law).
Wien Displacement Law: the product of the peak wavelength and the
temperature is found to be a constant. Wien was awarded the Nobel
Prize for Physics for the year 1911. |
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Infrared - how it works
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The sensor in an IR
thermometer collects a small amount of energy (usually 0.0001 watt)
radiated from the target, generates an electrical signal that is
amplified by a precision amplifier and converted into voltage
output.
A CPU digitizes the signal by a 16bit Analog-to-Digital Converter,
an Arithmetic Unit solves a temperature equation based on Planck’s
Radiation Law, compensates for the ambient temperature and
emissivity resulting in a temperature reading within a fraction of a
second after you push the “read” button on the IR thermometer. |
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FAQ
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Competitive IR Thermometers are much larger than ZyTemp’s.
ZyTemp IRTs are as small as the battery of some traditional IR
Thermometers. Is accuracy compromised?
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| Accuracy is not compromised.
Each IR Thermometer has a test report in our calibration database,
which is traceable by the serial number. Calibration tests adhere to
"ASTM E1256. Test Methods for Radiation Thermometers (Single
Waveband Type)" |
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Can IR thermometer measure air temperature?
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Yes and no. No, because air
(i.e., Oxygen and Nitrogen molecules) do not emit infrared
radiation.
However, you can aim an IR thermometer at anything having the SAME
temperature as the air such as a leaf or grass (under sunshade) or
indoors such as your desk, a piece of paper having the same
temperature as the air.
The key to measuring "air temperature" is to measure
"anything that should have the same temperature as the
air". |
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Can I measure the body temperature of an Ant by Infrared
Measurement Technology?
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You can aim the IR thermometer
at small object such as an ant, but what you measure is an average
temperature of the ant & the adjacent surface because the
Field-Of-View of the IR thermometer is much larger than the ant.
But, if a large collection of ants occupies the whole FOV of the IR
thermometer, then one can measure their average body temperature.
This FOV is the main consideration to obtaining the correct
temperature reading from IR thermometer. |
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How far away can I measure?
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Can one measure the
temperature of a wall from a 5-meter distance or the temperature of
a mountain from 1km? Yes as long as the FOV is filled by the target.
Also, many IRTs measure in the 8um to 15um wavelength band where the
atmosphere is almost totally transparent.
Can the IR thermometer operate in complete darkness? Yes, that's why
DOD & military are interested in IR.
In fact, early IR technology was developed by the military. |
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Can the IRT operated in complete darkness?
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Yes, that's why DOD &
military are so interested in IR.
In fact, the early IR technology was developed by military fund. |
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Can the IRT penetrate a building, measure what's inside?
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| No, because an IRT measures
surface temperature. |
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But I remember IR can penetrate something?
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| In the 8um to 15um wavelength
band IR can penetrate PE film (for example: a plastic trash bag).
You can hide something warm behind a PE film (such as your hand) and
the IR thermometer can detect the presence of the object. |
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Now can I measure the body temperature of a fish in my aquarium?
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No, water & glass are
transparent for visible light, but for IR, it's almost completely
"opaque". One can only measure the temperature of the
glass.
How about my pet's temperature? by pointing an IR thermometer at
your dog, you measure the surface temperature of the fur. What you
see is what you get. |
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How do I know, my IR thermometer is still accurate?
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Calibration of an IRT is
extremely sophisticated, that's why traditional IRTs are so
expensive, but not ZyTemp IRTs.
Radiant Innovation Incorporated (RII) has developed proprietary CCE
(Continuous Calibration Equipment), which simultaneously calibrates
up to 128 IRTs, at different temperatures, in a continuous,
high-throughput production operation.
RII is ISO9001 certified. |
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The target must occupy the
entire FOV(Field Of View) of the IR thermometer.
Avoid shining surfaces (metal), rough surfaces give better accuracy
(because of higher emissivity)
Adding Electrical Insulating Tape (black is better) on the metal
surface, can solve the problem, and give accurate result.
Be sure the tape is large enough to cover to Field Of View of the IR
thermometer.
Be sure the tape will not BURN. Use with caution!
Avoid temperature errors by not viewing nearby high-temperature
objects. Try to be perpendicular to the target surface. |
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