Design and Principle
Two highly accurate cycloid-shaped screw spindles mesh and rotate inside acylindrical housing with two overlapping holes in the form of a figure 8, which forms the measuring chamber.
The medium flows in axial direction and rotates the spindles, it is forced along the measuring chamber bores by the profile of the spindles. This happens without pulsation and with minimum leakage. A pickup will inductively detect the speed of the spindle pair through the housing via a pole wheel with a high number of gears.
The speed of the spindles is absolutely proportional to the volume flow over a very wide range. Pulses per volume unit will finally serve the evaluation (in addition an analogue signal 4 to 20 mA will be available when using the local display unit VTM. Please see pickup and ampli-fier datasheets). The K-factor (calibration factor) of the helical flow meter defines the exact pulse rate per litre.
We calibrate our flow meters to determine their K-factors, calibration records are part of delivery. When calibrating we consider as much as possible operating viscosities and customers’ specifications.