Idea for black body source

[mookins]

Hi,

I am trying to implement a low tech, quick "check" source for our radiation thermometers to ensure they are in good working order between calibrations again a calibrated black body radiation source.

My idea was to use an integrating sphere with an incandescent lamp as a source. Then two signals would be tapped from the sphere via fibre optic leads and then fed into two radiation thermometers. One of the two radiation thermometers would be an offline unit which is known to be in good working order, unlike those used in production.

I just want to know if this sounds feasible to you before I go drop a bit of cash having a go at it.

 

[Student100]

Hi,

I am trying to implement a low tech, quick "check" source for our radiation thermometers to ensure they are in good working order between calibrations again a calibrated black body radiation source.

My idea was to use an integrating sphere with an incandescent lamp as a source. Then two signals would be tapped from the sphere via fibre optic leads and then fed into two radiation thermometers. One of the two radiation thermometers would be an offline unit which is known to be in good working order, unlike those used in production.

I just want to know if this sounds feasible to you before I go drop a bit of cash having a go at it.

Here's a good paper on calibration and associated uncertainties: http://www.bipm.org/wg/CCT/CCT-WG5/Allowed/Miscellaneous/Low_T_Uncertainty_Paper_Version_1.71.pdf

Your idea will work, but for a quicker check why not use something like a hotplate with a settable temperature? The uncertainties are likely to be high regardless.

There are commercial black body sources you could purchase if you need higher accuracy, intergrating sphere's aren't the cheapest things in the world either.

 

[mookins]

Hi,

We have a commercial black body reference, a Mikron M335. Unfortunately due to the nature of the process, damage to the fibre optic leads and lenses is hard to avoid and common. We would like a way to check the instruments weekly, even daily if possible to ensure there is no recent damage that may have ocured to the lens or fibre optic lead.

The instruments are dual wavelength ratiometric pyrometers and measure from 700°C up to 1800°C. Due to the temperature range a hotplate soon becomes a miniature furnace and with that comes a whole host of other issues.

I am pursuing the original idea, but with a diffuser, https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=1660&pn=ED1-C20-MD
If that works well but needs something better I can then try an integrating sphere.

Thanks for the assistance, much appreciated and I will be sure to report back.

 

[Student100]

Hi,

We have a commercial black body reference, a Mikron M335. Unfortunately due to the nature of the process, damage to the fibre optic leads and lenses is hard to avoid and common. We would like a way to check the instruments weekly, even daily if possible to ensure there is no recent damage that may have ocured to the lens or fibre optic lead.

The instruments are dual wavelength ratiometric pyrometers and measure from 700°C up to 1800°C. Due to the temperature range a hotplate soon becomes a miniature furnace and with that comes a whole host of other issues.

I am pursuing the original idea, but with a diffuser, https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=1660&pn=ED1-C20-MD
If that works well but needs something better I can then try an integrating sphere.

Thanks for the assistance, much appreciated and I will be sure to report back.

Yes, no doubt those temps are a bit warm for the ol hot plate trick. :)

Good luck.