Like many other hobbyist we have always been fascinated by radioactivity and the sensors to detect it. Geiger-Müller tubes are a common and relatively inexpensive way to measure radiation. GRAD is a complete solution for radiation counting in an Arduino shield form factor. Its main features are dual tube support to increase sensitivity and very low power consumption.
The Maxim MAX6675 and the newer MAX31855 thermocouple to SPI interface chips are very popular with electronics enthusiasts because of their extreme ease of use combined with good accuracy.
Both devices however are only available in SMD package making breadboard prototyping very difficult without using a suitable breakout PCB. Standard thermocouple connectors are also not breadboard friendly further aggravating the issue.