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TMP006 - best housing materials

Mark Wagner
Prodigy 20 points
Other Parts Discussed in Thread: TMP006

What materials/thicknesses are recommended for the TMP006 to sit behind (that is, the device housing) in order to maintain greatest accuracy?

  • 0
    TI__Genius 12325 points

    Hi Mark,

    Would you be able to provide a bit more information about your application? Specifically, and information you can provide on the object being measured and the environment in which the TMP006 is installed would be helpful. Strictly speaking the device does not have to be housed to maintain the level of accuracy quoted in the datasheet, I recommend taking a look at  the "TMP006 Layout and Assembly Guidelines" document (SBOU108) for design tips to maximize the part's accuracy.

  • 0 in reply to John Caldwell
    Prodigy 20 points

    For a consumer electronics device that will be carried around by a user and used to measure body temperature and other items.  The document you mentioned is for PCB layout, I'm talking next step, the PCB needs to be protected by some kind of mechanical housing (i.e. plastic/metal).  I can't just leave the system exposed to the outside world, where dust and moisture can be present.   If the TMP006 is sitting behind this housing, what kind of materials will work well to transmit the IR required?  I was thinking of window material but I haven't found a lot of transmittance data for different plastics in the 4-8um band mentioned in other posts. 

    Whatever I use, unless the transmittance is ~100%  I'll have to adjust the data stream coming out of the TMP because it won't be seeing all the energy (or am I mistaken).

  • 0 in reply to Mark Wagner
    TI__Genius 12325 points

    Mark,

    Here is a presentation on several different lens/window materials and their associated transmission over wavelength, the first two pages detailing polyethylene and polypropylene may be the most relevant in your search for a suitable enclosure material.

    7080.Lens_Materials.ppt

    Edmund Optics also produces an IR window material: http://www.edmundoptics.com/products/displayproduct.cfm?productID=2043

    You are correct that you will have to scale the data coming from the TMP006 to account for the reduced transmission through the window material. This can be accomplished with a two point calibration procedure as detailed in the TMP006 user guide in section 6 "Calibrating the System" starting on page 10. The S0 term is a "sensitivity factor" that compensates for the accumulation of signal reductions throughout the system.

    7288.TMP006 Device User's Guide.pdf