Continuous vol. measurer for liquids of low viscosity and gases - comprises displacement counter magnetic coupling and servomotor with pulse scanning

摘要

The displacement counter (1) with an inlet (2) and outlet (3) for the medium to be measured is driven by the servomotor (5) via a magnetic coupling (4). A pulse scanner (6) forms a unit with the motor. The signal frequency delivered by the former is proportional to the vol. of the stream flowing through the counter per unit of time. After passing a pulse shaper (7), this signal frequency appears at the terminal (8) as a measurement signal as well as at the input of the function generator (9) as a control signal. This function generator presents the approach to the characteristic of the counter (1) as U1 = f(Q,n). U1 is the input value for the amplifier (10) at whose output a voltage U2 = f(Q,n) appears. ADVANTAGE - Simple conception with servo-drive but without separate differential pressure detection. High precision even at flows below 1 1/h. Allows adjustment of average calibration factor to uniform value.