Smart Geiger Counter Radiacode-102 with Free Mobile App. Nuclear Radiation Detector.

Excellent sensitive beta and gamma pocket scintillation meter. However, if you use it in microsieverts per hour mode (rather than counts/second), beware (1) it responds to beta radiation so you get a misleadingly HIGH indication of deep tissue dose in typical situations where both beta and gamma are present (it is not an "energy compensated" gamma dose rate meter, so the detector is not shielded to mimic the shielding of soft beta and low energy gammas by the skin), and (2) even for high energy pure gamma emitters, it indicates free-air dose rates which are typically 50% higher than the shielded deep tissue/bone marrow dose rates. In summary, you will tend to get over-estimates of your actual deep tissue gamma dose, unless you correct for shielding by soft tissue. (So either use it in counts/second mode, or multiply dose equivalent readings by 2/3 to get accurate deep tissue dose in ~1MeV gamma ray energy fields.)Apart from that, it is a lightweight, senstitive gamma detector and spectrometer. All software and instructions are online. To turn on, hold the round button down. To turn off, you need to press the round button once to bring up the menu on the right edge of the screen, then scross down using the "bar" scroll switch (located between the screen and round button), select the on/off symbol (a line in a partial circle), and then press the round button!The rechargable 3.7v lithium ion battery is apparently glued inside the case, so eventually you will need to break it open to replace the battery (or use it permanently on USB power from an external USB power supply).

Works perfectly