It never hurts to collect more data, and I often find myself wanting to record temperatures from a few extra animals. Most (all?) commercial thermocouple dataloggers that will record temperatures from multiple thermocouples cost several hundred or thousands of dollars. I set out to put together a relatively cheap 8-channel thermocouple datalogger based on the open-source Arduino development platform.
Thermocouple Type-K Glass Braid Insulated – K. Thermocouples are best used for measuring temperatures that can go above 100 degC. This is a bare wires bead-probe which can measure air or surface temperatures. Most inexpensive thermocouples have a vinyl covering which can melt at around 200 degC, this one uses a fiberglass braid so it can be used in high temperature measurements such as heaters and ovens.
Thermocouple Amplifier (MAX6675) breakout board. Thermocouples are very sensitive, requiring a good amplifier with a cold-compensation reference. The MAX6675 does everything for you, and can be easily interfaced with any microcontroller, even one without an analog input. This breakout board has the chip and bypass capacitor assembled and tested. Comes with a 2 pin terminal block (for connecting to the thermocouple) and pin header (to plug into any breadboard or perfboard). Goes great with our 1m K-type thermocouple.
Works with any K type thermocouple
0 to 1024 degree C output in 0.25 degree increments
3.3 to 5v power supply and logic levels
SPI data output requires any 3 digital I/O pins.
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