User Manual

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Product Description

• EASY TO USE

With the Meriam Model M334 you can check,

calibrate and measure all your current signal

instruments in a 4 to 20 milliamp DC loop. It can

be used at any access point in your loop. Source &

Read 0.00 to 24.00 mA, Simulate a 2 Wire

Transmitter or use the Meriam Model M334 to

simultaneously power your 2 Wire Transmitter and

measure its output. When desired the Meriam

Model M334 can display current in milliamps or

percent of 4 to 20.

• SOURCE MILLIAMPS

Calibrate recorders, digital indicators, stroke valves

or any instruments that get their input from a 4 to

20 mA loop. Easily set any value quickly to within

0.01 mA with the adjustable digital potentiometer

“DIAL” or use preset 4.00 mA (0.0%) and 20.00

mA (100.0%) EZ-CHECK™ settings.

• RECALL OUTPUT SETTINGS

The EZ CHECK™ switch provides rapid checking

of 4.00, 20.00 and any convenient third point

between 0.00 to 24.00 mA.

• CALIBRATE USING LOOP POWER

Check loop wiring and receivers by using the

Meriam Model M334 in place of a 2 Wire

transmitter. Simulate a changing process input to

check loop response and control settings. The

Meriam Model M334 uses any loop power from 2

to 100V DC.

• READ LOOP CURRENT

Check controller outputs or measure the milliamp signal anywhere in the loop. The Meriam

Model M334 measures 0.00 to 52.00 mA signals with greater accuracy than a typical multimeter.

The Meriam Model M334 can be easily switched to display milliamps or percent of 4 to 20.

• POWER & MEASURE 2 WIRE TRANSMITTERS

The Meriam Model M334 can simultaneously output 24V DC to power any and all devices in a

process loop using the internal batteries and the internal switching power supply, while

measuring the output of a 2 Wire Transmitter and any other loop devices. This is handy for

checking the functionality of transmitters in the field or on the bench.

• READ DC VOLTS

The Meriam Model M334 can measure from -99.99 to +99.99 VDC with 10mV resolution. Use it

to check loop power supplies, I/V converters, chart recorders, 1 to 5 Volt signals, and any other

voltages within this range making it unnecessary to carry an additional multimeter.

Meriam Model M334

4-20 mA Loop Calibrator

Operating Instructions

Meriam Model M334

4-20 mA Loop Calibrator

Operating Instructions

Meriam Process Technologies

10920 Madison Ave. • Cleveland, OH 44102 Tel: 216.281.1100 • Fax: 216.281.0228 • sales@meriam.com • www.meriam.com

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Summary of content (8 pages)

PAGE 1
Meriam Model M334 4-20 mA Loop Calibrator Operating Instructions Product Description • EASY TO USE With the Meriam Model M334 you can check, calibrate and measure all your current signal instruments in a 4 to 20 milliamp DC loop. It can be used at any access point in your loop. Source & Read 0.00 to 24.00 mA, Simulate a 2 Wire Transmitter or use the Meriam Model M334 to simultaneously power your 2 Wire Transmitter and measure its output.
PAGE 2
Basic Operation w SOURCE / READ / 2 WIRE SWITCH Select “SOURCE” to output in milliamps or percent. Select “READ” for reading in milliamps or percent. Select “2 WIRE” to simulate a 2 Wire Transmitter. e EZ-CHECK™ SWITCH Instantly output 4.00 mA or 20.00 mA by moving the EZ-CHECK™ switch to the “4.00mA” / “0.0%” position or “20.00mA” / “100.0%” position. For fast three point checks select the “DIAL” position. The Meriam Model M334 will remember the last “DIAL” value, even with the power off.
PAGE 3
Sourcing Milliamps mA OUT, % OUT (Percent of 4 to 20 mA) Choose this function to provide an output from 0.00 to 24.00 milliamps. The compliance voltage is a nominal 24 VDC to provide the driving power to your milliamp receivers. 1) Disconnect one or both input wires from the device to be calibrated. 2) Select “mA” or “% 4 to 20mA” with slide switch q. 3) Select “SOURCE” using slide switch w.
PAGE 4
Simulate 2-Wire Transmitters 2 Wire mA, 2 Wire % (Percent of 4 to 20 mA) Choose this function to simulate a 2 Wire Transmitter output from 0.00 to 24.00 milliamps. Operates in loops with power supply voltages from 2 to 100 VDC 1) Disconnect one or both input wires from the device to be calibrated.
PAGE 5
Read DC Volts READ V Choose this function to measure from -99.99 to +99.99V DC. 1) Select “READ VDC” with slide switch q. 2) Connect the red (+) and black (-) leads of the Meriam Model M334 across the voltage source to be measured. Any DC voltage from -99.99 to +99.99 volts may be measured. Loop power supplies, signal voltages at receivers, batteries and transmitter voltage drops may be measured. Signals exceeding ±99.99 VDC will be indicated by OVRLD on the display.
PAGE 6
Application Notes SETTING UP VALVES When setting up a valve it is important to correctly set the end stops. Use the Meriam Model M334 to supply the 4 to 20 mA control signal to stroke the valve. Select “SOURCE” and the Meriam Model M334 will use the internal power source for outputting current or switch to 2-WIRE SIMULATOR to stroke a valve using any pre-existing installed loop power supply as the power source.
PAGE 7
Meriam M334 Specifications (Unless otherwise indicated all specifications are rated from a nominal 23 °C, 70 % RH for 1 year from calibration) General Operating Temperature Range -20 to 60 °C (-5 to 140 °F) Storage Temperature Range -30 to 60 °C (-22 to 140 °F) Relative Humidity Range 10 % ≤RH ≤90 % (0 to 35 °C), Non-condensing 10 % ≤RH≤ 70 % (35 to 60 °C), Non-condensing Size L=5.63 x W=3.00 x H=1.60 inches Weight 12.1 ounces (including boot & batteries) Batteries Four “AA” Alkaline 1.
PAGE 8
Meraim M334 Specifications (continued) (Unless otherwise indicated all specifications are rated from a nominal 23 °C, 70 % RH for 1 year from calibration) Source/Power & Measure Two Wire Transmitters M334 Ranges and Resolution 0.00 to 24.00 mA Full Span or -25.0 to 125.0% of 4-20 mA Accuracy EZ Check(s) at 4 & 20mA1 0.0 to 24.00 mA ≤ ±0.025% of Span at 4 mA & 20 mA (± 0.005mA) ≤ ± 0.05% of 24.00mA Span (± 0.01mA) Noise ≤ ± ½ Least Significant Digit Temperature effect ≤ ± 0.