Ultrasonic position measurement system for hydraulic cylinders, has transceiver in pre-chamber and processor comparing reference and piston reflections

摘要

An ultrasonic position measurement system has a transceiver (10) in a pre-chamber (6) sending signals into a hydraulic fluid (4) in a cylinder and processes time differences for received reflected signals from a reference reflector (9) and piston (1) surface phase boundary (5) to obtain the distance to the piston and to use the reference to control the transmitted intensity. Includes INDEPENDENT CLAIMs for the procedures used by the system and for the use of measured temperature and pressure and physical modelling to calculate the nominal attenuation in the fluid.