Product Description 
 Set alarm value the Alarm User YHW300 surrounding rock abscission instructions according to the actual situation, overrun automatic alarm (LED light indication); infrared data communications, real-time ionospheric data, the data transfer to the computer processing draw graph; micro-reactive consumption design, built-in battery can work continuously for more than one year; measurement accuracy is high, and put an end to the human reading error. 
 YHW300 the surrounding rock ionospheric instructions the technical parameters of the Alarm 
 Range :0-150mm / 300mm 
 Measuring range :0-20m 
 Measurement accuracy: 1%