Principle Of Operation; Electrical Description; Hp Series Specification - Hoffer Flow Controls HP Series User Manual

PRINCIPLE OF OPERATION

The HP Series Profile/Insertion Flowmeter is a velocity measuring, turbine type
flowmeter.
The flowing fluid engages the vaned rotor causing it to rotate at an angular
velocity proportional to the fluid flow rate.
The angular velocity of the rotor results in the generation of an electrical signal
(AC sine wave type). Summation of the pulsing electrical signals relates directly
to the total flow. The frequency of the signal relates directly to the flow rate.
The vaned rotor is the only moving part of the flowmeter.

ELECTRICAL DESCRIPTION

The pickup coil furnished with the flowmeter is a sensing device that converts the
motion of the rotating rotor into essentially an AC sine wave.
Pickup Coil - The variable reluctance pickup contains a permanent magnet and
associated wire-wound coil and the modulated carrier pickup contains an
oscillator and associated wire-wound coil. For both coil types the movement of
the of the rotor blade across the coil tip produces an AC signal within the coil
winding.
Pickup Coil Output - As described above is transmitted by the shielded cable to
the electronic instrumentation for proper factoring, display, and control.

HP SERIES SPECIFICATION

Materials:
Stem, Housing, Rotor Support – 304 stainless.
Bearing – 440SS shielded ball bearings, hard carbon composite,
Rotor – 17.4 stainless (Standard), Nickel 200, 430 stainless.
Seals – Rulon (Standard), Viton, Teflon.
End Fittings:
Flanged and NPT threaded are available.
Electrical:
Connections – Terminal block in conduit enclosure. Flying leads for
Pickup – Variable reluctance type, nominal DC resistance 1300 ohms
Frequency Range – 0 to 500 Hz.
HP-208
tungsten carbide sleeve.
preamp or two-wire transmitter.
(standard). Minimum output level 10 millivolt RMS.
– Modulated Carrier type, nominal DC resistance 11.5 ohms.
Page 8 of 17 HP Insertion Meter