Hi I am building a temperature datalogger that will plot a real time graph on a PC.
The basic spec is:-
- 13 Channel data logger with K-Type Thermocouples
- Measure Temperature range 4c to 120c at a resolution 0.01c
- Sample rate 4 readings of all channels per second
- Arduino – Sends all 13 Temperatures over USB Serial communication to Laptop running a Visual Basic Application plotting real time temperature graph, saves and loads results.
- The thermocouples are placed across a thermal block to validate temperature across the block and measure temperature non-uniformity.
So far, I have the programmed an application with Visual Basic that plots the data and saves the plot and can load a saved temperature trace.
I have used the Maxim DS18B20 temperature sensors instead of thermocouples basically because I could buy some so cheap it was worth it to prototype a sketch on the Arduino that would read temperatures and send them over serial communication via the Arduino usb port and to create the visual basic application to validate the temperatures and plot them.
Now I have this side working I need to take the plunge into using thermocouples and understand the need for cold junction compensation, for the resolution I think I’m right to say I need a 20/24 bit ADC.
I also will need to multiplex the thermocouples.
I am struggling to find any boards that will fit the spec does anybody know of any suitable boards or solutions, even if I build the circuit myself?
Any help, advice, nudge in the right direction gratefully appreciated…….