Is it possible to take a signal from a K type thermocouple and split it into two outputs, a 0-5v reference signal and a mV signal (same signal produced by TC)? I am looking to control a device with the 0-5v signal while sending the same mV thermocouple signal to a temperature display gauge.
If you're connecting to the K-type directly then you only have microvolts available so you would need to amplify that to bring it into the sort of range that the Arduino's crude ADC can handle. You'd also need a DAC to generate the analog output voltage. It would probably work out a lot simpler just to buy a thermocouple amplifier that provides the outputs you want.
Use two thermocouples?
...R
since the thermocouple does not have a 0-5 output, are you talking about a temperature transmitter ?
can you offer a drawing or maybe a data sheet ?
one typically takes the output of the thermocouple ( TC ) and then sends that to a circuit that will scale it for use. you can buy a commercial unit. and that would send out a signal . you buy the unit based on the thermocouple type. you cannot mix them.
and you order based on the output you want. few offer dual outputs. it is usually 4-20ma or 0-5v but not both.
please give us more information before we start offering solutions without details.
Hi, you can buy electronic temperature gauges that read and display from the K-type AND also output 0-5V or 0-10V analogue output as well.
http://www.brainchild.com.tw/bc/electronic-temperature-controllers.html
Tom...... 
Thanks for all the advice! Before I go any further, I must warn you that I am very new to the Arduino platform (I still need to purchase one) and I come from a medical background with no coding experience. With that said, I am looking to fabricate my own autoclave by injecting water into a flash boiler for steam production. The heater I am using has an integrated thermocouple that I wanted to split as a signal for both the PID controller (Watlow EZ Zone Controller) and the Arduino . I was thinking of running the thermocouple to a gauge with a 0-5v ouput signal however I will lose the PID controller.
Tgomeza1:
I was thinking of running the thermocouple to a gauge with a 0-5v ouput signal however I will lose the PID controller.
I may be misunderstanding your point, but if you have a 0-5V signal then that is an ideal input to the Arduino for use in a PID temperature controller. So I'm not sure how this results in your 'losing' the PID.
The Watlow PID controller uses the K type thermocouple and as far as I know there is no 0-5v temperature output option
You really need to have some idea of the internals of the temperature controller.
Thermocouples by definition, use a "hot junction" which is at the measurement point, and a "cold junction"; the temperature measured is the difference between the two. The cold junction is usually inside the measuring equipment and for accurate measurements, its temperature is in turn measured by a thermistor or semiconductor to compensate for "ambient" temperature (which gets quite hot inside the autoclave casing; it certainly does in mine! :D).
This means that simply bridging some other apparatus across the thermocouple wires as they enter the controller is probably not practical.
I kind of figured that it would be difficult if not impossible to split the TC signal between the PID controller and the Arduino without doing some complex work. Would it be possible to have the ardiuno act as the PID controller with some method of activating a 20amp/120vAC solid state relay? If so, any links to similar projects? I figure I can control the heater while providing a 0-5v reference signal for water to inject.