Brochure

Masoneilan 12400 Series Digital Level Transmitter/Controller | 3

With a combination of features such as smart filtering, HART

communication protocol compatibility and an optional

4-20 mA analog output signal, GE’s Masoneilan 12400 Series transmitter/controller offers exceptional process

control for a wide range of applications - even severe service. Easy to install and operate, it is the first torque

tube-type level instrument that integrates level transmitter and switch functions in a single device. Plus, the

12400 Series transmitter/controller is engineered for optimum efficiency, upgradeability and reliability making it

a cost-effective investment for the long term.

Overview

The Masoneilan 12400 Series instrument is a two-wire, loop-powered level transmitter with HART

Communication that operates according to the fully proven buoyancy and torque tube principles. A change in

liquid level varies the net weight of the displacer (2), increasing or decreasing the load on the torque tube (4)

by an amount directly proportional to the change in liquid level. The resulting rotation of the torque rod (6) and

attached magnets (7) modifies the magnetic field surrounding a non-contact sensor (8), producing an analog

signal proportional to the level in the vessel. This analog signal is converted into an error-free digital signal that

is processed by the on-board micro-controller. After processing, the digital result is converted to a 4-20 mA

analog output signal.

This sensing method is non-contacting and frictionless, and it provides total isolation between the sensed

motion and sensor output.

Sketch showing the arrangement of

the different parts.

In black: torque tube, arm and

displacer

In red: mechanism and displacer

chambers

In blue: instrument head

1 - Displacer chamber

2 - Displacer

3 - Torque arm

4 - Torque tube

5 - Torque tube housing

6 - Torque rod

7 - Magnets

8 - Non-contact sensor