INTOODUCTION
The Preso Gemini Cone meter is a differential pressure device that combines excellent performance with many benefits
including low maintenance, low head loss and a unique ability to have none/minimum straight pipe runs in front of the
meter The Gemini Cone meter produces a pressure differential across a pair of pressure measurement ports The movement
of a fluid around the cone-shaped element creates a pressure differential between an upstream and a downstream pressure
port, which is processed by a differential pressure transmitter to provide the flow rate The conical shape of the element also
causes the flow meter to act as a flow straightener, pre-conditioning the flow and making the Gemini Cone meter a versatile
measuring instrument for many applications Badger Meter takes pride in designing an optimized differential pressure
metering solution for your system
Theory of Operation
The Preso Gemini Cone meter creates a differential pressure that is proportional to the rate fluid flow A transmitter measures
the differential pressure and outputs an integrated electronic signal, typically via Modbus or a 4…20 mA output, to a flow
computer or other process controller for interpretation and readout For compressible fluids, line pressure and temperature
measurements are required for accurate flow rate calculations as well as compensation for the adiabatic change in the
expansion factor As fluid flowing through the pipe flows around the cone, a pressure drop occurs The static line pressure (P1)
is measured via a wall tap located just upstream of the cone Pressure is also measured via a sensing tap that is connected to
the cone and measures pressure at a point immediately downstream of the cone (P2) The fluid flow rate is calculated from the
difference between the two pressures using variations of the Bernoulli flow principles and equations
∆P
High Pressure
Port (
P1
)
Low Pressure
Port (
P2
)
Support and Cone
Assembly
Meter Body
Flow
Figure 1: Principles of operation
Applications
The Gemini Cone meter is designed to work in unprocessed and processed applications, and is ideal for applications that
present a wide range of measurement challenges The Gemini Cone meter is a great solution for steam and boilers, coke oven
gas, multiphase (non-homogeneous) fluids, biogas and industrial gas management
Introduction
Page 6
June 2018
DPM-UM-00206-EN-03
