Application: beating shaft diameter detection, textile machine detection, valve position detection and control, roll gap measurement, vehicle brake wear etc. Summary Differential transformer displacement sensor (LVDT) is widely used in aerospace, machinery, textile, construction, railway, coal, metallurgy, plastics, chemical industry and scientific research institutions such as the national economy, is used to measure the elongation, vibration, the thickness of the object, the expansion of high technology products. The pen type displacement sensor has excellent performance and is suitable for the measurement of high precision and high repeatability in the quality control and measurement applications. The probe is made of silicon nitride ceramics with high hardness and the precision of the moving part of the shaft is made of precision guide rail. Pen type displacement sensor with transmitter with transmitter output standard DC signal transmitter with 12~24VDC power by the electronic circuit sealed in 304 stainless steel tube, can work in damp and dust and other harsh environments, the output signal is the standard can be a computer or a PLC using 0~5V, 0~10V, 4~20mA，RS485.