dianxiaobao_1M18Engine speed sensor.magnetic speed sensor M18screw sizecopper material this speed sensor is for all kinds Diesel generator set.but please make sure the screw size is correct.This product is a magnetic speed sensor, which is installed next to the engine's flywheel, the engine rotation speed sensor senses the AC signal, proportional to its frequency and engine speed. Speed sensor and supporting the use of the tachometer to measure engine speed. This product has a simple structure, easy installation, stable quality, reliable performance.The main performanceAmbient temperature: -30 ~ 120 degreeMaximum sense voltage: 50V ACMounting thread: M18-1.5 68mmPrecautions1 The products use a wrench to tighten the threaded engine, maximum tightening torque of 49N * m2 proximity sensor nose to the top surface of the gear is 1mm3 has two output terminals of the sensor, the sensor should be between the tachometer output and reliable connection with shielded cable to ensure smooth transmission. skillsrequirement:1.Thesensorisinstalledontheflywheelhousing, and the distance from the sensing head to the top of the flywheel gear is adjusted 1-1.5M2.The sensor plug resistance is 10001009.3. One end of the plug is connected to the negative power supply of the tachometer, and the other end is connected to the signal end of the tachometer.