What performance can be expected from the FSR03CE if it is operating at or near 90°C for extended periods of time? Will it function at that temperature? How long will it last? What kind of signal integrity will it maintain at that temperature? Will it degrade at that temperature?
Hello horace.tucker, welcome to the Forum community. The datasheet states that the operating temperature for FSR05CE-ND is –20 to +85°C, so operation at 90°C would not be recommended. We do have these options that have a wider temperatre range of -54°C ~ 120°C.
I understand it is not recommended. Not my question. I want to know if it will continue to operate with any accuracy just above that temperature, and if so, how well and for how long.
I’m not sure of that, but I will e-mail your questions to my Product Specialist for his reply. I’ll get back to you as soon as I have that information for you.
The datasheet indicates that a shift in resistance of several percent can be anticipated after only 10 days or so at elevated temperature:
Almost certainly, at least in some sense. Whether or not it will do so in a way suitable for what you have in mind is a different matter.
That’d depend on your failure criteria, applied stresses, and a number of other factors. A meaningful answer is nearly impossible to offer without getting very specific as to such things.
Seeing as it offers almost none to begin with, not much. Devices of the sort are quite sloppy, and not really aimed at measuring so much as detection. Successful applications will need to tolerate long-term drift in device parameters such as overall resistance, sensitivity, etc.
Of course, it’s simply a question of rate. Many chemical and physical processes that contribute can be described by an Arrhenius relationship, which predicts roughly a doubling of rate for every 10°C increase in temperature. But again, one would need to define application conditions and failure criteria in order to be specific about such things, and the nature of the opportunity would inform a manufacturer’s willingness to entertain such discussion.
Operating temperature ratings are given more for purposes of placing boundaries on the other specs/characteristics mentioned than describing the limits of the part itself; one does not expect a part rated to 85°C to immediately disintegrate at 85.00001°.
The target operating temperature isn’t that far off-label as to rule out evaluating the product for your needs, but starting out with realistic expectations would be important.
Thank you for the detailed, informative, and thorough answers. My biggest take-away is that an FSR is probably not my best solution. I’ll have to hunt for another device that can provide force data reliably over time at temperature. The problem is distance. I don’t have much leeway in thickness.
The manufacturers data sheet says they wouldn’t count on it.
The odds are good that if you try this with a few dozen they might all work at an acceptable* level for an acceptable* time (* to you).
If you want to use a few hundred maybe, for a few thousand you could get lucky, larger quantities you’d be foolish to try.
Of course, because the manufacturer clearly says no, the liability is all yours.
Thanks for the information. That’s what I’ve been learning along the way. For our purposes, we are looking at adding force indicators to our existing equipment so we have actual in-place data, and not just calculated and assumed values. The biggest problem I am facing is space constraints. That’s why I was looking at FSR: they are very thin.