Research Article

Study of Magnetic Interference on an LVDT: FEM Modeling and Experimental Measurements

Table 2

Summary of experimental results.

ItemVoltage supplyCurrent supply

Feeding signal amplitude3.5 V (3.5)23.0 mA (24.0)
Transformation ratiofrom 0.48 (0.54) to 1.69 (1.66)from 0.48 (0.54) to 1.70 (1.66)
Ratiometric rangefrom −0.58 (−0. 50) to 0.57 (0.50)from −0.57 (−0.5) to 0.57 (0.5)
Voltage swing (V)4.30 (3.90)4.35 (3.90)
Non linearity error (%)1.11 (0.7) in (−20 mm, 20 mm)
0.14 (0.11) in (−10 mm, 10 mm)
1.12 (0.7) in (−20 mm, 20 mm) 0.15 (0.11) in (−10 mm, 10 mm)
Primary voltage repeatability (mV)0.8 (no interference)
2.5 (with interference)
1.5 (no interference)
8 (with interference)
Secondary voltage repeatability (mV)1.6 (no interference)
2.9 (with interference)
2.1 (no interference)
8.8 (with interference)
Measured position uncertainty (micrometers)11 (no interference)
15 (with interference)
13 (no interference)
52 (with interference)
Position drift values (micrometers)from 71 (72) to −44 (−72)from 58 (72) to −25 (−72)
Position drift uncertainty (micrometers)1955
Agreement with simulations (characteristic curve) (%)>85 in (−20 mm, 20 mm)
>95 in (−10 mm, 10 mm)
>86 in (−20 mm, 20 mm)
>92 in (−10 mm, 10 mm)
Agreement with simulations (ratiometric) (%)>83>84