This mini-Gamma sensor uses a 4x4x8mm Cesium Iodine (Csl) scintillator that uses a radiation-sensitive crystal as the detection component. It works with a PIN diode to convert the radiation to electric outputs. Along with a high sensitive preamplifier, the Csl crystal and PIN diode are encapsulated into a 18.2x12.2x6.4mm metal enclosure. This compact mechanical design enables the sensor to be used in small digital devices such as smart phones, smart watches and other wearable devices used for those who are sensitive to radiation.

The output pulse amplitude correlates with the energy of the incident radiation particle. For incident particle energies below 1.2 MeV, the pulse amplitude is proportional to the radiation particle energy. The output pulse counting rate is also proportional to the radiation intensity in the measurement field. However, the applied voltage should come from stable DC power supply with minimal or no ripple, as ripple can couple with the input of the highly sensitive preamplifier, causing fault signals.