Quantity: one piece Size: 135 68 25 mm Measuring range: 20Hz2000MHz Display unit: m/cm2 (microwatts/square centimeter) Test error: 10 w/cm2 (microwatts/square centimeter) Sampling rate: about 5 times/second Operating temperature: 0-40 Operating humidity: less than 70% RH Alarm mode: sound and light alarm Digital display range: 0-1999 w/cm2 (microwatts/square centimeter), if it exceeds, it will be displayed as: 1 Mobile phone high-frequency radiation detection method: Turn on the power switch and place it near the phone. In standby mode, the instrument generally does not display. (If the mobile phone is still beyond the standard, the mobile phone can basically be discarded); Then use the phone to call the test mobile phone, and the radiation value of the mobile phone will be displayed on the detector display screen, accompanied by light and sound alarms. Because electromagnetic waves are constantly changing, the displayed numbers may also jump within a certain range. Low-frequency radiation detection methods for household appliances: Turn on the power switch and place the front of the instrument facing the target to be measured. If there is radiation, the radiation value will be displayed on the detector display, accompanied by light and sound alarms. Because electromagnetic waves are constantly changing, the numbers shown above also constantly change within a certain range. Detect radiation protection products or hold the radiation protection card in your hand and place it between the instrument and the target to be detected, and the effect of the radiation protection products can be seen from the change in the display value. Test range: Electromagnetic radiation of lower frequency band electrical equipment such as family room, office, computer room, control room, high voltage line, computer, TV, copier, fax machine, cable, Bluetooth wireless system, monitor, air conditioner and radiation protection products and high frequency of mobile phone Electromagnetic radiation test. Precautions: 1. Please turn off the device when not in use to extend battery life. 2. When is displayed on the screen. The battery (9V battery) should be replaced immediately. battery not includedGood quality product