Joined: 27 July 2007
Location: AR
Posts: 5

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I decided to make a chamber with a peltier cell in order to get low temperatures and measure it by MLX90614ESF-AAA. Also for sensor soft development. I can not read the real temperature from the object placed 7 cm far. I can read my own body temperature and other objects temperature correctly but distance is a hard topic. I am thinking about the object material. It is an aluminium heat sink. Perhaps factory filters or material Emissivity must be considered. Do you have experience with this? do you have an idea about? How I can get better result with object place not too close from the sensor? I check with fresnell lenses, 1 zone 2 cm diameter but I can not get better and real values. I am using factory default single zone SMBus. Thank you

Joined: 1 January 2005
Location:
Posts: 19

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Hello Jose,
Did you consider the field-of-view specification? The sensor has a 90 degree field of view, so the measurement area has a diameter of 14cm at a distance of 7cm. The sensor will average the temperature of everything it can see.

Depending on the surface treatment, there's a wide variation in emissivity. You can google "aluminum emissivity" for more details.

Joined: 7 December 2005
Location: BE
Posts: 64

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Metals are very difficult to measure because of the low emissivity. Aluminnium is no exception. The emissivity depends a lot on the surface state of the aluminium (oxidation). Getting emissivities from the web will not give much help.
You also have to consider that due to the low emissivity, the aluminium will reflect the energy of its surroundings like a mirror, and you will measure the temperature of what is around the aluminium instead of the aluminium itself.
If possible, a much better option is to paint the amluminium with a high temperature paint like the ones used for barbeques.

Regards,

Luc Buydens