# Crt thermister surface coating



## NoIdea (Jul 19, 2011)

Hi, anyone delt with these little fella's, any idea as to the surface coating on the ceramic disc/disc's found inside, tried nitric acid many years ago(when i had access to it) with little to no effect. If my memmory serves me right, the ceramic reacted more, over time, than the surface coating.

Thanks


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## NoIdea (Jul 19, 2011)

NoIdea said:


> Hi, anyone delt with these little fella's, any idea as to the surface coating on the ceramic disc/disc's found inside, tried nitric acid many years ago(when i had access to it) with little to no effect. If my memmory serves me right, the ceramic reacted more, over time, than the surface coating.
> 
> Thanks


Got a pic if that helps.


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## johnny309 (Jul 24, 2011)

sensor applications.
NTC THERMISTORS
The NTC thermistors which are discussed herein
are composed of metal oxides. The most commonly
used oxides are those of manganese, nickel, cobalt,
iron, copper and titanium. The fabrication of
commercial NTC thermistors uses basic ceramics
technology and continues today much as it has for
decades. In the basic process, a mixture of two or
more metal oxide powders are combined with
suitable binders, are formed to a desired geometry,
dried, and sintered at an elevated temperature. By
varying the types of oxides used, their relative
proportions, the sintering atmosphere, and the
sintering temperature, a wide range of resistivities
and temperature coefficient characteristics can
be obtained.

Hope this help. And below is the full article.

http://www.thermometrics.com/assets/images/ntcnotes.pdf


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## NoIdea (Jul 24, 2011)

Wow, aswum stuff, thanks Johnny  

Obviously i bin looken in the wrong places.

Again .... Thanks

Deano


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