2 wires PC thermometer in arduino

I'm riding a casemod, and will create a system for monitoring temperatures of certain parts of the computer, but the LM35 sensor is too large to be placed in certain parts of my computer, I like to use a thermometer made for computer but it has only 2 wires, and the LM35 has 3 pins, as do the temperature reading with my other thermometer having only 2 wires?

This is the thermometer that I mean:

http://www.com-tra.de/img/p/temp_sensor.jpg

PS: Sorry for my bad english :P

The JPG appears to be a thermocouple but I guess it could be a thermistor. Lots of DVMs with temperature measurement capability have similar looking probes.

If you just need 1 degree accuracy, why not use an inexpensive thermistor an 1% resistor in a voltage divider configuration?

http://www.instructables.com/id/Arduino-thermometer-LCD-Display-Thermistor/

Ray

mrburnette: The JPG appears to be a thermocouple but I guess it could be a thermistor. Lots of DVMs with temperature measurement capability have similar looking probes.

If you just need 1 degree accuracy, why not use an inexpensive thermistor an 1% resistor in a voltage divider configuration?

http://www.instructables.com/id/Arduino-thermometer-LCD-Display-Thermistor/

Ray

I would use these thermometers because I already have them, so do not need to spend money to buy others. They already come with the cables (with sleeves) and they are fine as well, since I need to measure the temperature of very small places ...

That looks like a probe-in-film exactly what I have but mine is already connected to a digital thermometer made for use in computers in the way you intend. The probe will get in anywhere. The sensor is a thermistor, so just buy a resistor and do as Ray says.

Nick_Pyner: That looks like a probe-in-film exactly what I have but mine is already connected to a digital thermometer made for use in computers in the way you intend. The probe will get in anywhere. The sensor is a thermistor, so just buy a resistor and do as Ray says.

Well, a lay question, which resistor I need to put him able to measure the temperature with this thermometer? :p Im very newbie in the electronic part :p

gabrielhowat: which resistor I need to put him able to measure the temperature with this thermometer?

I'm afraid mine is in the little black box I bought off eBay, but there is a great swag of tutorials. This not hard, primary school maths will suffice, and it is mostly done with lookup tables.

Well, a lay question, which resistor I need to put him able to measure the temperature with this thermometer? :p

Many thermistors are marked @ 25 deg C. At around 75 - 77 F, measure the thermistrr resistance with a good DVM. The resistor, unless you can find a data sheet) can be a standard value resistor as close to the thermistor value. Use a 5% or 1% resistor. You will have to plot your own lookups or you can try using Steinhart–Hart equation to calculate the temperature. http://en.wikipedia.org/wiki/Steinhart%E2%80%93Hart_equation

In my projects, the Steinhart-Hart math works quiet well even on an Uno.

Ray