M334 4-20mA Loop Calibrator


The Meriam M334 is a technologically advanced, highly reliable, and ruggedly constructed milliampere calibrator designed for ease of use. It includes all the necessary functions for troubleshooting and calibrating 4-20mA loops. It provides sourcing and reading of milliamperes, as well as power supply, measurement, and simulation of two-wire transmitters. Additionally, it can measure DC voltage to troubleshoot power supply issues.

The M334 is functionally equivalent to similar calibrators but offers numerous additional benefits. These improvements include enhanced long-term stability, accuracy, reliability, and durability (including significantly extended battery life). The comprehensive enhancements to the Meriam M334 enable it to meet or exceed the expected performance of comparable products.

While maintaining the familiar, time-tested reliability and user-friendly features of similar calibrators, the M334 also surpasses the performance levels of many higher-cost calibrators and meets the most demanding requirements of today—this is the new standard!



Advantages of the M334


All Milliampere (mA) Current Loop Functions:

Source 0.00 to 24.00mA (-25.0% to 125.0%)

Source 0.00 to 52.00mA (-25.0% to 300.0%)

Simulate Two-Wire Transmitter

Power and Measure Two-Wire Transmitter


Accuracy Better Than 0.025%:

4.00 & 20.00mA EZ-Check within 0.005mA error


Large High-Contrast Graphic Display:

Visible in all lighting conditions and angles


Voltage Display Function:

Displays 0.00 to ±99.99 VDC


EZ-Dial Buttons:

Conveniently adjust output in 0.01mA increments (0.01%)


EZ-Check 3-Position Slide Switch:

Instantly outputs calibrated values of 4.00 or 20.00 milliamperes

All three positions can be adjusted for convenient valve testing

Sturdy, rugged, and resistant to breakage with splash protection


Uses 4 Standard AA Alkaline Batteries:

Battery life up to 70 hours under normal use

Easy access battery compartment


Overload Protection:

135 VRMS protection

Fuse-free protection against accidental incorrect connections


Compact, Lightweight, and Durable:

Small size with heavy-duty rubber protective housing


Optional Rechargeable Battery:

One-hour quick charger and four (4) NiMH batteries

Kit includes an AC adapter and a car travel charger adapter