Don't Sacrifice Reliability When It Comes to Your Level Transmitter

Mar 11, 2024
3 min read

Updated: Aug 13

Performance and reliability are what you expect in a level transmitter - but traditional magnetostrictive transmitters have long been associated with reliability issues around installation, setup, and connectivity. The Jerguson® JMT™ Series Magnetostrictive Transmitter was engineered specifically to solve this.

The Problem with Traditional Magnetostrictive Transmitters

Reliability issues with traditional magnetostrictive transmitters typically show up in three places: installation (fitting the transmitter to the actual chamber configuration on hand), setup (getting the unit properly configured and communicating), and connectivity (maintaining a stable signal once in service). Any one of these can turn a straightforward instrumentation upgrade into a drawn-out troubleshooting exercise.

How Magnetostrictive Measurement Actually Works

A magnetostrictive transmitter measures the time interval between the initiation of a current pulse and the detection of a return pulse. The electronics generate a pulse and create a magnetic field along the length of a sensor wire mounted externally to the magnetic level gage chamber. When the magnetic field of the float interacts with that wire, a return pulse is sent back to the housing. The electronics then convert that time interval into a 4-20mA loop-powered output signal.

Float magnet strength matters directly to measurement quality here: a magnetic level gage float with a strong magnetic field - such as floats using an Alnico 8 ring magnet - helps achieve real-time, highly accurate readings, since a weaker field produces a less distinct return pulse for the electronics to interpret precisely.

The JMT Solution: Patent-Pending Signal Capture

With patent-pending signal capture technology, the JMT Series can be mounted on almost any chamber configuration without sacrificing reliability. This flexibility addresses the installation problem directly - rather than requiring a specific chamber design to guarantee reliable signal capture, the JMT's technology is built to perform consistently across a wide range of configurations.

Dual-Entry Enclosure and One-Touch Diagnostics

The dual-entry enclosure allows for safe access to the HMI, where a single touch of the button provides current level information, transmitter settings, and a live graph showing the real-time waveform. This addresses the setup and troubleshooting side of the reliability equation - rather than working blind, a technician can see the transmitter's actual real-time signal behavior directly at the unit.

Full Technical Specifications

4-20 mA loop powered; 12.5 to 36 VDC
HART Protocol Communication Standard (HART 7 EDDL Pending)
Sensing lengths from 12 inches (305mm) to 360 inches (9 meters)
Process temperature -300°F to 700°F (-185°C to 372°C), with insulation safeguards required over 350°F (176°C)
ETL approved for USA, Canada, ATEX, and IECEx (Explosion/Flame Proof, Intrinsic Safety)
Dual compartment NEMA 4X; IP66 enclosure
Epoxy coated aluminum standard; 316SS optional
One-touch waveform graphical display

This is a genuinely wide operating envelope - a 9-meter maximum sensing length and a process temperature range spanning nearly 1,000 degrees Fahrenheit reflects a transmitter engineered for demanding, variable service conditions rather than a narrow standard application.

Why This Matters for Connectivity and Long-Term Reliability

The JMT is designed to work and be fully configurable with generic HART communication, supporting integration into existing plant control systems without requiring proprietary communication hardware. Combined with hazardous-location approvals across multiple regulatory frameworks (ETL, ATEX, IECEx), the JMT is built to maintain reliable connectivity and signal integrity across the full range of industrial environments it might be installed in - not just idealized lab conditions.

Applications

The JMT Series Magnetostrictive Transmitter is used across:

Power Generation: Feedwater and process tank level monitoring requiring continuous transmitted signal
Chemical Processing & Refining: Applications requiring wide temperature range and hazardous location approval
Oil & Gas: Separator and process vessel level monitoring with HART integration
Any Application Requiring Reliable Continuous Level Output: Across variable chamber configurations