Hi,
This is for my first arduino project.
I am looking for a temperature sensor to measure temperatures between 130 and 160°C.
I would like to use 8 of them with my arduino uno.
Do you have any advice on witch modele I can use (type DS1820 but with higher temperature range I guess ?)
How often do you want to sample? 10/sec -- 1/hour
How about precission? how many digits after decimal .
How about accuracy? error in reading
Power consumption? watt
Distance to controlboard?
many questions. Maybe you can tell about what you want to realize? the more you tell the better the advice!
Have you checked - http://www.temperatures.com/ - ?
I'm not aware of any digital sensors that will work much higher than 100C. Also beware that a star topology (even more than 2" leads from a main line) with the 1-wire sensors creates signal echo problems. Making use of the Arduino's analog inputs rather than using digital can be a little more economical as well. I think there are some pretty cheap 4 channel analog multiplexers you can use since you don't have 8 analog ports on the Uno. In practice most sensor systems still use analog signals. Digital sensors don't guarantee accurate or reliable readings, and the reliablilty part can be particularly troublesome with longer wire lengths. I'm sure opinions vary, but I would recommend a thermistor. I think the thermistor documentation is all a bit obtuse, but basically you can either use a lookup table or go with the Steinhart-Hart equation, which is a fairly easy calculation for the Arduino. The common voltage divider circuit used with thermistors is a very important concept to understand, and has lots of uses for sensing.
Slightly more advanced, but very similar in technique is an instrustrial sensor commonly known as the PT100 or PT1000 (100ohm or 1k resistance at 0C), which uses a small platinum wire and has a PTC (increasing resistance). You can find those on eBay pretty cheap. Like thermocouple's they will work at several hundred degrees.
You can find code samples and help with all of this in the playground. As you would expect lots of people have spent time thinking about temperature measurement, so there is an amazing amount of detail out there.
Digital or analog, you'll still find plenty of noise in your data, so check out the post on the single pole filter technique to smooth it out.