Temperature Influence on Position Transducer for Pneumatic Cylinder

In this paper, temperature sensitivity of inductance position transducer of a pneumatic cylinder system is presented. The magnetic solid iron rod and aluminum piston position changes the inductance of the tubular coil around the aluminum pneumatic cylinder. The measurement and finite element method are used to evaluate inductances versus piston position at different frequencies. Temperature effect on the coil inductance is analyzed. Temperature of the iron rod and the aluminum cylinder are changed for the temperature sensitivity analysis. The measured iron rod temperature dependence is in the order of 0.45 %/°C at 100 Hz and 0.27 %/°C at 200 Hz. Finally a small compensating solenoid coil is used at one side of the cylinder (entrance side for piston) to compensate temperature dependency effects.