1. History of IR

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 invest huge amounts of money in IR for military application.
In 2004 ePlus Premium has designed the most compact and premium outlook Pen-type IRT.

1.1 What is Infrared Ray?
IR, just like any light ray, is an Electromagnetic Radiation with lower frequency (or longer wavelength).

Fig. 1: Wavelength Spectrum of IR Thermometry

Anything above absolute zero (-273.15 degrees Celsius or 0 degrees Kelvin), radiates in the infrared.
Even ice cube, snow, your refrigerator emit infrared.

1.2 Why I can't see IR?
God design your eyes for Sunlight, not for Infrared.
Infrared is an invisible light, though your skin can sense it.

2. Tutorial

2.1 How it works?
The sensor in this IRTcollect the tiny energy (usually 0.0001 watt) from the target, amplify by a precision amp, convert it into voltage output. The CPU then digitize the signal by a 16bit Analog to Digital Converter, the Arithmetic Unit then solve the temperature equation by the above Nobel Prized Laws , and compensate the ambient temperature and emissivity effect.

2.2 As I remember, usually IRT are much larger than this one? Accuracy is compromised?

In the past, IRT were much larger, but ePlus Premium IR0 – series is as small as the “battery of some large IRT”, and in a perfect Pen shape. However, performance Accuracy is not compromised, in terms of measurement range, accuracy, response time, and repeatability. Size doesn't matter!

2.3 Can IRT measure air temperature?
No and Yes.
No, because Air do not emit infrared, the emissivity is too low to be detected.
Yes, because you can pointing the IRT to anything that has the SAME temperature as the air:
Outdoor: leaf , tree, grass (under sunshade) has the same temperature as the air
Indoor: your desk, a piece of paper, has the same temperature as the air.
The key to get “Air temperature” is to measure “anything which should have the same temp as the air”

2.4 How can I get the correct reading from IR0-series?
The target must cover the whole FOV(Field Of View) of the IRT.
The D:S ratio of IR0 series is 1:1. It means you shall keep the IR0 in a distance less than the diameter of target spot.

Some tips
Avoid shining surface(metal), rough surface give better accuracy.
add Electrical Insulating Tape (black is better) on the metal surface, can solve the problem, give accurate result.
be sure the tape is large enough to cover to Field Of View of the IRT.
be sure the tape will not BURN. use with caution!
Avoid temperature noise (avoid other High temperature object is nearby)
for example: you are measuring an IC, with a solder-iron nearby
Try to perpendicular to the target surface.

2.5 How far ?
Can you measure temp. of a wall from 5meter? Temp. of a mountain from 1km?
IR0 series is sensing the 8um to 15um infrared, the atmosphere is almost totally transparent for this band.
At 100meter, no rain, no fog condition, IR0 series is very accurate, not matter how far away from the target.

2.6 Can the IR0 series operated in complete darkness?
Yes, that’s why DOD & military are so interested in IR.
In fact, the early IR technology are developed by military fund.

2.7 How do I know, my IRT is still accurate?
Calibration of IRT is extremely sophisticated, that’s why IRT were so expensive.
IR0 series is calibrated by an automatic Calibration Equipment, and passed three times 100% accuracy check under production.

If still in doubt, you can try this DIY-Calibration:
1. Fill a large polystyrene (e.g., Styrofoam) cup (10 oz or larger) (or any Thermos) halfway to the surface with crushed ice.
2. Add cold tap water to ? to 1 inch below the rim of the cup tip. Two cups, one inside the other, will provide better insulation and more stable temperatures throughout the test.
3. Immerse the tip of an accurately calibrated contact probe thermometer, that has been calibrated, into the water and vigorously stir the water’s surface with the probe for one minute, or until contact probe temperature stabilizes.
4. When the probe temperature has stabilized, continue stirring the water, while taking simultaneous temperature measurements with the IR thermometer.
5. Hold the IR thermometer within 1 inches of the surface of the water for the most accurate measurement. Infrared temperature
measurement should be within +/-1℃ (+2℉) of probe reading at 0℃(32℉).

Warning: because such a testing requires special technique; and for the follow reason, ePlus Premium has no guaranty on the result.

2.8 What else can I use IR0 series to measure?
You can measure the temperature of almost anything, including the universe!

2.9 About material:
These material has high emissivity (good for IR0 series):
plastic, glass, ceramic, cloth, skin, water, milk, ground, tree, leaf

These material has low emissivity (bad for IR0 series):
gold, aluminum, any shining metal

for details, see the attached Emissivity Table.

Courtesy by www.ZyTemp.com