Fukushima Nuclear Power Plant Accident caused booming demand for radiation measurement instruments not only among the Japanese population, but also among people throughout the world. The finished goods warehouses of the well-known dosimeters manufacturers were left empty in the first week after the accident, while some little-known device manufacturers began to appear in the world market, having felt an opportunity to make money out of a high demand. This situation seems quite logical. However, the devices that have not been properly tested and have been made with deviation from regulatory requirements can become a source of MISINFORMATION about the real radiation situation of the environment and cause panic in people who are not very much familiar with this subject and cannot check or deny the results obtained from these devices.
In 1986 Ukraine faced such a problem, when after Chernobyl NPP accident a big number of different devices got into the exclusion zone showing different readings in one and the same place. Sometimes, the results differed substantially. Expert analysis of this problem revealed the main cause of divergences in the measurement results between different devices. The reason for this proved to be the incorrect compensation of energy dependence of the dosimeter’s detectors (dependence on gamma-quanta energy). This incorrectness showed itself in excessive measurement results under conditions of mixed radiation fields (from different types of radionuclides) that occurred in the areas contaminated with radioactive emissions from the damaged reactor. Because of this fact, the Ministry of Emergency Situations of Ukraine, which was responsible for creating new radiation measurement instruments, decided to conduct field tests of each new radiation survey device in the Chernobyl exclusion zone. Thus, the newly created radiation measurement instruments of “ECOTEST” TM underwent relevant field studies before entering the market. It is not surprising that the Ukrainian devices work correctly not only in the metrology laboratories but in the real environment. No wonder that extreme tours members in the Chernobyl NPP exclusion zone prefer Ukrainian radiation measurement instruments of “ECOTEST” TM, as they were many times convinced in strange behavior of “Radex” type and similar devices after crossing the checkpoint of NPP’s 10-km strict control zone.
A striking example of divergent results of background radiation measured by two different dosimeters is the video report of extreme Japanese journalists, which appeared on YouTube at http://www.youtube.com/watch?v=yp9iJ3pPuL8.
Journalists used two types of dosimeters during their trip, measurement results of which differed significantly. Which of the devices can be trusted then? A desire to immediately identify these devices arises: to find out the type, model and manufacturer of the instrument. Having taken a closer look at these devices, we see that the type of the device, its name and trademark of the manufacturer is clearly visible on the yellow device – Dosimeter-Radiometer MKS-05 “TERRA-P” of “ECOTEST” trademark. These data are enough to find maximum information about the product and its manufacturer in the Internet. As for the black one, we cannot find anything else but for the inscription saying that this device is a personal dosimeter. Thus, the user will have to decide on his or her own, which device can be trusted.