I am working on a project that requires my team to monitor the temperature of an exhaust pipe. We would be monitoring fairly high temperatures (around 1000°C). We were planning to use a DAQ but the project is low budget so we were looking for alternatives. I found out about the Arduino today and it seems like it might be a good alternative. All I want to do is be able to send the voltage reading from the thermocouples to a LabView program. I have a way to calibrate the thermocouple readings. I was wondering if anyone had any ideas as to how to approach this.
Since the thermocouple output is a few millivolts you won't get very good resolution with the Arduino D/A converter. You might want a chip designed for thermocouple interface like the Maxim MAX6675: http://www.maxim-ic.com/datasheet/index.mvp/id/3149
Another possibility that allows going beyond 1024C is a low-voltage instrumentation op-amp such as INA128 (You'd need to run with +/-2.5V split rails and use a gain of about 120. That gives about 4 degress per LSB on the Arduino's ADC, allows upto 1500C. You would need to take care with the output range since it isn't rail-to-rail and you'd probably want to take the difference of output to the mid-rail analog ground via two analog pins. Type-K thermocouples are roughly 10.25uV per degree so even at 1000C its only a 10mV signal (which is why instrumentation amp with low input offset is needed).
BTW I don't call 1000C a "fairly high" temperature, its close to the melting point of copper.
If you go with an instrumentation amplifier you need a second temperature sensor to measure the temperature of the cold junctions. The thermocouple measurement is relative to the temperature of the cold junction.