Foxboro multivariable transmitter redesigned for optimum natural gas flow rate measurement

Foxboro multivariable transmitter redesigned for optimum natural gas flow rate measurement


The IMV25 Multivariable Transmitter now combines flexibility, economy, and accuracy with Modbus digital communications


FOXBORO, MASSACHUSETTS, USA – Invensys Process Systems has redesigned the Foxboro IMV25 multivariable transmitter for optimum natural gas flow rate measurement and other natural gas applications that rely on accurate measurement of pressure, differential pressure and process temperature. The IMV25 product line is now available with Modbus digital communications for remote monitoring, configuration and calibration; a new process interface structure for flexible installation; extended measurement ranges; and the industry’s longest standard warranty.

“The IMV25 multivariable transmitter provides economy and flexibility for natural gas flow measurement applications by enabling customers to replace separate static pressure, differential pressure, and temperature transmitters with a single transmitter that digitally communicates all three measurements to the customer’s system. This saves not only the cost of the separate transmitters, but also the costs and issues associated with separate transmitter installation, wiring, and setup. Now we are able to make these benefits available to customers who are using Modbus communications protocol and support them with our new best-in-class warranty,” says Joseph Downey marketing director for the Foxboro Measurements & Instruments Division of Invensys Process Systems.

The IMV25 multivariable with Modbus digital output allows remote monitoring, configuration, and calibration. The Modbus version communicates with host processors using the Modbus RTU mode through a two-wire RS 485 multidrop serial connection, which provides high data throughput at common baud rates. The IMV25 is also available with HART and FoxCom communications, as well as an assignable 4 to 20 mA output signal.
A configurator software package for Foxboro Modbus multivariable transmitters, Model PCMM, has also been introduced to provide convenient transmitter setup. Communications are accomplished through either a serial or USB-to-RS485 converter.

A common process connection technique for natural gas flow measurement applications is to mount transmitters directly to a three- or five-valve manifold assembly that is supported by the process piping. To make this direct mounting easier, a new Low Profile™ structure has been added to the IMV25 multivariable transmitter. The Low Profile structure uses a compact sensor body to reduce the overall height of the transmitter and to allow use of process covers with process connections facing downward. This allows customers to use a common installation design for both competitive Coplanar™ and Foxboro Low Profile transmitters.

Low Profile transmitters are available with compact three or five-valve manifolds and are offered with an optional adapter plate to allow installation directly onto existing Coplanar manifolds for easy retrofit.

The IMV25 is configurable for DP spans as high as 840 inH2O (210 kPa, 2100 mbar) and AP spans as high as 5300 psi (36.5MPa, 365 bar or kg/cm2). To better handle small span applications, a new 10 inH2O (2.5 kPa, 25 mbar) maximum DP span sensor has been added to the line.

The IMV25 now comes with a five-year standard warranty, the industry’s longest standard warranty offering. Invensys has recently extended the warranties on its Foxboro pressure transmitters from two years to five years, and supports these warranties with a rigid quality assurance procedure for tracking defect rate, quality control and field performance.