FIELD: measurement equipment.
SUBSTANCE: method to measure the flow rate based on the measurement speed of a turntable mounted in the flow over the motor shaft, determination of the inflection point of the frequency of rotation of the vane from one of the electrical parameters of the motor power and determination of the flow rate, speed of the turntable, corresponding to the point of inflection. However, the power of the motor is modulated by a harmonic signal. The inflection point of the envelope is determined by the change in the spectral components of harmonics sum and difference of frequencies. The apparatus comprises a turntable, a turntable speed sensor, the motor connected to the turntable, a harmonic signal generator, devices to identify the 2nd harmonic and to calculate the flow rate, by speed of the turntable, corresponding to minimisation of the 2nd harmonic signal.
EFFECT: improving the accuracy of measurement, simplification and speed.
6 cl, 5 dwg
