1. [Measurement object]: Needle-free hygrometer can measure four different materials (dry wall, brick, cork, hardwood), which can meet most materials in daily life. It is one of the indispensable tools in the family. Press the "" or "" key to select the measurement mode 2. [Alarm]: When the value of the measured object of the wood hygrometer exceeds the range, an alarm will be sent. In dry wall and masonry mode, the wood hygrometer with value>70% will give an alarm; In softwood and hardwood mode, the wood hygrometer will give an alarm greater than 17% 3. [Easy to operate]: The ambient temperature and humidity will be displayed on the screen of the wood hygrometer. Click the / button to switch the temperature unit, and click the "HOLD" button to lock the humidity value of the measured object. If there is no operation within 10 minutes, the wood moisture meter will automatically turn off 4. [Protect the measuring object]: The needleless hygrometer is mainly used to measure the humidity value by sending and receiving high-frequency electromagnetic wave signals to the measuring object through the sensor on the back. The measurement speed is fast, the measurement results are accurate, and no damage marks will be left on the measured object 5. [Measurement requirements]: the measured value of the drywall moisture meter represents the average value of the water content of a region, and the detection area is 40 * 40 * 20mm; The electromagnetic wave emitted by the drywall hygrometer can penetrate 20 mm