Measurement of radiation doses in soil and air contaminated with radioactivity
Easy to use by connecting to a smartphone for portability

From fine dust, radioactivity, pesticide eggs to sanitary pads, concerns about the environment are growing in our daily lives. There is a product that can help ease these concerns.

Pocket Geiger from Radiation Watch, a subsidiary of REVV, is one such example. Radiation Watch is an NGO non-profit organization, and Pocket Geiger is a portable radiation meter that measures the level of radiation in the atmosphere. It can measure soil or air contaminated with radiation.

Connect the sensor to your smartphone and you can measure the radiation levels in the air in as little as 30 seconds or as much as 2 minutes. It performs as well as expensive radiation meters used in the field.

Most of the existing field radiation measuring devices adopt the Geier-Muller counter (GM) method. The GM measuring device is the cheapest among field measuring devices, but it has a good detection ability for its price and a wide radiation measurement range. The measurement efficiency is somewhat lower, but it is less affected by external factors such as temperature.

Pocket Geiger uses silicon semiconductors to achieve precise measurements and portability with a small size. The GM meter uses a glass tube as a pressurized gas tube. This part is filled with solid particles to embed p-type silicon and n-type silicon inside the device, and the principle is that the measured value is obtained by forming the depletion zone of the irradiated radiation and increasing the radiation-induced current.

It can be used to monitor accumulated radiation levels in the surrounding area or to detect radon, a type of radiation, in the home. Radiation sources are divided into alpha, beta and gamma. Alpha rays can be shielded with a single sheet of paper, and beta rays can be shielded with metal. Gamma rays have a short wavelength, so they can only be blocked with lead or concrete. Pocket Geiger detects and measures gamma rays and X-rays.

Also, alpha particles produced by radon gas can be detected. To measure radon gas using a pocket Geiger, activated carbon or charcoal must be used. The method is to place charcoal in the place where radiation is to be measured for 1 to 3 days and then measure the radiation level. There are differences depending on the region, but if the measured value is 0.4 μSv or higher, it can be considered dangerous.

A common use is to monitor radiation in the air and soil, but extremely low levels of radiation are generally not detectable, except in food or water that is heavily contaminated with radiation.

Currently, there are Type 3 and Type 4 products available for purchase. Type 3 can be used on smartphones running iOS and Android, but requires a separate battery. Type 4 is exclusive to iOS, and can only be used on iPhones and iPads, and can measure without a separate battery. Both products have a measurement range of 0.05 μSv/h to 10 mSv/h and operate at temperatures between 0 and 40 degrees. The product size is 34x70x36 and it weighs 40g, making it portable.

Radiation Watch also has a product that connects to a smartphone to measure fine dust. It measures the size of PM2.5, which is called ultrafine dust, and PM10, which is fine dust. It measures using laser scattering and can measure in the range of 0 to 999㎍/m3.