Extending Temperature sensor

[sianjohn]

Anybody knows how to extend temperature sensor from 125 deg. to 1000 deg.....

Please help me with this....


Thanks

[languer]

Well, you could use a sensor meant for such a range (I'm not sure if thermistors would work).

Or you could thermally isolate the sensor such that 1000º is equivalent to 125º. But then, you would not be able to resolve low temperatures.

[octavio bru]

As you dont mention the sensor you are planing to use it is difficult to advise, but I am absolutely shure that a sensor of the DS1820 style will melt at those temperatures.

To get onto that range you should go to use a "K" type temperature probe.

Thare are various threads on the group about those sensors and how to use them.

Sorry about my bad english

[sianjohn]

Thanks for the replies you"ve made it is right that i plan to use d1820...but i got problem when i verify its datasheet it is too low for the project...

My plan is to make temperature sensor for my wife gasrange using 16f887 triac and nichrome to make the heat stable using +/- varying of electric heater and gas, any suggestion about this...

please do... i am very eager to know all of your idea that will help this project...



Thanks

Angelo

[BigWumpus]

Try this:

AD595 mit an Type K Thermocouple and maybe 12V voltage,
a very good voltage-divider to convert 10V to 5V ;-),
a very good 5V-reference for the AD-Part of the PIC,
10 Bit resolution,
a table of the real temperature compared to the voltage ...

look inside the datasheet !
I've made an Excel-sheet of the temperature vs. voltage and so I got the %-error for every 100°. So I could interpolate the real temperate.

[J. Mark Wolf]

The Maxim MAX6675 part will work fine for you. It's a K-type to SPI interface chip, good to 1024 deg C. I've used it, works good.

[sianjohn]

Thank you for assistance i will try this chip i'll wait for the parts to arrive...

Thanks