LENGTH MEASURING DEVICE

In a length measuring device with a measuring transducer system, the curve of two sinusoidal test signals is dependent on the longitudinal movement of the measuring transducer system. An interpolation circuit delivers two high-resolution rectangular pulse sequences F1, F2 corresponding to the interpolated sinusoidal voltages and offset by 90 DEG , to an evaluating circuit. To achieve a high-resolution at low speeds of travel and a low-resolution at high speeds, two rectangular pulse sequences S1, S2 or G1, G2, offset by 90 DEG and giving a low-resolution, are additionally derived at the interpolation circuit. A control logic circuit 19 monitors the test voltages for attainment of a certain value of the longitudinal movement per unit time or speed of travel. The control logic circuit lets only the low-resolution rectangular pulse sequences through to the evaluating circuit when this value is exceeded, while it lets the high-resolution rectangular pulse sequences with the low-resolution rectangular pulse sequences when this value is not reached.