We designed a very high accuracy temperature sensor board for use with 3.3V Arduino devices as a part of a university project. The sensor board can provide ± 0.1 degree C absolute accuracy, very high resolution (24 bit ADC) and I have measured the repeatibility to be under 0.01 degrees C. The sensor board uses the tsys01 temperature sensor by Measurement Specialities, is breaboard friendly, provides input protection agains over and reverse voltage and is factory calibrated. There is also an Arduino library for it and it can be now bought from the Elecrow web shop.