Today I want to share a useful tool – thermal camera for smartphones. During circuit design or troubleshooting, thermal cameras can directly “see” the temperature distribution. So that it’s easy to find thermal issue during design. There are only a few brands of thermal cameras on the market. I have used Flir one pro and Seek compact pro before. Recently I got one Infiray T3S. Below is my test and comparison.

from left to right – Flir one pro，InfiRay T3S，Seek compact pro

Basic Comparison of Specifications

1.   Size, Weight and Material

a.    Size

Flir one pro is slightly bigger because it also contains a regular camera. InfiRay T3S has bigger lens. Seek compact pro is the smallest.

Size Scores

Size of cameras

b.    Weight

All of the three models are light weighted.

• Flir one pro – 38g
• Seek compact pro – 15g
• InfiRay T3S – 40g

Weight Scores

c.    Material

Cover material affects camera’s ruggedness, weight and electro-magnetic radiation protection.

• Seek compact pro – it feels like cheap plastic

• InfiRay T3S – it has metal cover. That’s why it is heavier. It is also anodized. The metal cover not only protects internal circuit better but also has electromagnetic radiation protection. So that it can work properly under certain environment such as transformer stations.

• Flir one pro – the cover is also plastic but feels soft, which provides protection in case it drops on the ground. The lens is not protruding which makes it less easy to damage.

Material Scores

d.    Lens.

The working wavelength of thermal imaging is 7-14µm. The best lens material is Germanium. Some producers use less expensive synthetic materials. According to my investigation and directly consulting with manufactures. I got the lens materials are as follows:

• Flir one pro – vulcanized synthetic material
• Seek Compact pro – vulcanized synthetic material
• InfiRay T3S – Germanium

Lens size- Flir one, Seek Compact Pro, InfiRay T3S

For infrared application, Germanium has best transmission of 95%. It can reach 99% with AR coating. Versus synthetic material can reach 95% with AR coating. Generally, cameras with better lens get clearer pictures and accurate temperature measurement.

Lens Scores

2.   Image Quality

The main functions of thermal cameras are imaging and temperature measurement.

Resolutions of the three models are:

• Flir one pro       – 160×120，with regular camera 1440×1080 pixels
• Seek Compact pro – 320×240
• InfiRay T3S      – 384×288

Let’s compare the images.

a.    Close-up Image

­­After overlapping with visible light, images from Flir one pro improves a lot. The thermal image and regular image are matched pretty well.

Image from Seek compact pro looks similar to Flir one ‘s 160×120. Even it is 320×240.

Image from InfiRay T3S is much better. The 384×288 pixels gives more- detailed and rich, sharp image.

Close-up Image Scores

b.    Close-up Portrait

Images from Flir one pro are better than the one from Seek compact pro, even its resolution is lower. The overlapping needs improvement because the visible and thermal images don’t match very well.

I took many pictures with Seek compact pro but could not get good one. The lady’s hair and background almost mixed.

Image from InfiRay T3S is much clear. Even the lady’s face detail and hair can be seen.

Close-up Portrait Scores

c.    Medium Range Image

Above pictures were all taken at about twenty meters distance.

The images of Flir one can hardly distinguish subject and the reflection from floor. And the thermal and visible image overlap matching problem is more obvious.

Seek compact pro is better than Flir one pro on details. The person and its reflections can be distinguished.

Image from InfiRay T3S is the best. The person’s head, arms, legs can be seen clearly.

Medium Range Image Scores

d.    Long Range Image

The image from Flir one pro without visible overlap is very blur. With visible overlap the different floors can be seen.

Seek Compact pro is better. Windows can be distinguished.

InfiRay T3S can “see” windows more clearly, and other details such as logo on the building, street lights and trees.

Long Range Image Scores

From all images mentioned above, InfiRay has best image quality. It provides more detail and rich display.

3.   Temperature measurement

• Flir one pro       range -20–400℃， accuracy ±3℃ or ±5%
• Seek compact pro       range -40–330℃, accuracy unknown.
• InfiRay T3S      range -20–120℃, accuracy ±2℃ or ±2%

InfiRay T3S doesn’t have widest range but has best accuracy. ±2℃ or ±2% is the industry standard so it can be directly used on professional industries such as electric power industry. As for circuit design, since people could get burned with PCBA that is above 60℃, -20–120℃ is more than enough.

a.    Body Temperature Measurement

• Flir one pro – 35.5℃
• Seek Compact pro – 33℃
• Infiray T3S – 36.13℃

The measurements from Flir one pro and InfiRay T3s are close. And they match with normal body temperature. The measurement from Seek compact is quite off.

Body Temperature Measurement Scores

b.    PCBA Temperature Measurement

Flir one pro, with the help of visible overlap, can see positions of components, however the problem is that the thermal and visible images not match well.

Seek compact pro is hard to find positions of components. Just could barely see PCBA itself.

InfiRay T3S got a clear image and easy to locate the components that has highest temperature.

PCBA Temperature Measurement Scores

c.    Parameter Settings

Parameter settings affect measurement accuracy. All three models have emissivity setting. Flir one pro and Seek compact pro both provide a few fixed options. It’s easy for regular users, however, advanced users are not able to set emissivity for specific material to get accurate measurement. InfiRay T3S has emissivity, ambient temperature, humidity, distance settings to fine-tune the measurement. This function is very helpful for hardware engineers to get accurate temperature measurement.

Parameter Settings Scores

4.   Battery Lifetime

Flir one pro equipped with battery that needs to be charged before use. Seek compact and InfiRay T3S are powered by smartphones through USB connection.

The battery lifetime of Flir one is very short. It only lasted about thirty minutes when I used it. When ambient temperature is lower, the battery lifetime is even shorter.

Battery Life Scores

5.   Conclusion

Comprehensive Scores

Considering materials, image quality, temperature measurement accuracy, InfiRay T3S is the best and highly recommended. (All rights reserved. Please indicate the source if repost)

Ulani Uriah

Umar Nisar was born and raised in the busy city of Abbottabad. As a journalist, Umar Nisar has contributed to many online publications including PAK Today and the Huffing Post. In regards to academics, Umar Nisar earned a degree in business from the Abbottabad UST, Havelian. Umar Nisar follows the money and covers all aspects of emerging tech here at The Hear Up.

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