Instrument for measuring the flow rate of a liquid in a vessel having a stirrer

Conclusions

• 1. The proposed instrument, by virtue of the small dimensions of the tube diameter and propeller, does not induce significant distortions in the shape of the flow motion. This is facilitated by the magnet being separated from the coil and the distance from the edge of a propeller blades to the magnet being 10 mm.

• 2. A change of the magnet's properties does not affect the instrument's calibration characteristic, since the instrument records not the value of the emf but the number of pulses generated.

• 3. The liquid flow in a vessel having a stirrer has a nonuniform character. Therefore the instrument indications must be averaged. In using pointer-type instruments and recorders this is difficult, because of the presence of a large number of subjective errors.

  Use of the PS-20 counting instrument, which records and sums the pulses for a fixed time interval, affords a significant reduction of measurement error.