MASTECH MS2138 Digital Clamp Meter Multimeter

1. Introduction

The MASTECH MS2138 is a reliable digital clamp meter designed for a wide range of electrical measurement tasks. With its multifunctional capabilities and user-friendly features, this tool is ideal for both professionals and hobbyists. This manual provides essential information for the safe and effective operation of your MS2138 clamp meter.

2. Safety Information

WARNING: To avoid electrical shock or personal injury, read and understand all instructions before using this meter. Always operate with the battery cover securely closed.

• Always inspect the meter and test leads for any damage before use. Do not use if damaged.
• Do not apply more than the rated voltage, as marked on the meter, between terminals or between any terminal and ground.
• Use caution when working with voltages above 30V AC RMS, 42V peak, or 60V DC. Such voltages pose a shock hazard.
• Always disconnect the circuit power and discharge all high-voltage capacitors before testing resistance, continuity, diodes, or capacitance.
• Do not operate the meter around explosive gas, vapor, or dust.
• Ensure the rotary switch is in the correct position for the desired measurement before connecting the test leads to the circuit.
• When making current measurements, ensure the circuit is de-energized before clamping the meter around the conductor.

3. Package Contents

Upon opening your MASTECH MS2138 package, please verify that all items listed below are present and in good condition:

• MASTECH MS2138 Digital Clamp Meter
• Test Leads (Red and Black)
• Carry Bag
• User's Manual (this document)
• Calibration Certificate

Note: Batteries (3x 1.5V AAA) are NOT included in the delivery and must be purchased separately.

The MASTECH MS2138 Clamp Meter, its packaging, operation manual, calibration certificate, test leads, and batteries (not included in delivery).

4. Product Overview

Familiarize yourself with the components of your MS2138 clamp meter:

Front view of the MASTECH MS2138 showing the LCD display, rotary switch, function buttons, and input terminals.

Close-up of the clamp jaw, used for non-contact current measurement, and the integrated work light.

Rear view of the meter, indicating the battery compartment and safety warnings.

Dimensions of the MASTECH MS2138: 225mm (height) x 86mm (width) x 32mm (depth).

5. Setup

5.1 Battery Installation

1. Ensure the meter is turned OFF.
2. Locate the battery compartment on the back of the meter.
3. Use a screwdriver to open the battery compartment cover.
4. Insert three (3) 1.5V AAA batteries, observing the correct polarity (+/-).
5. Replace the battery compartment cover and secure it with the screw.

Note: The meter will display a low battery indicator when the batteries need replacement.

6. Operating Instructions

The MS2138 features a rotary switch to select measurement functions and buttons for additional controls.

6.1 Basic Operation

• Power ON/OFF: Rotate the central dial from 'OFF' to any desired function to power on. Rotate back to 'OFF' to power off. The meter features auto power off to conserve battery life.
• Function Selection: Use the rotary switch to select the primary measurement type (e.g., V~ for AC Voltage, A~ for AC Current).
• 'FUNC' Button: Press this button to cycle through sub-functions within a rotary switch position (e.g., AC/DC voltage, resistance/continuity/diode/capacitance).
• 'RANGE' Button: Toggles between auto-ranging and manual ranging. In manual ranging, press repeatedly to select desired range.
• 'REL' Button (Relative Measurement): Stores the current reading as a reference value. Subsequent measurements will display the difference from this reference.
• 'Hz/%' Button (Frequency/Duty Cycle): Used to measure frequency or duty cycle in relevant modes.
• 'HOLD' Button: Freezes the current reading on the display. Press again to release.
• 'MAX/MIN' Button: Records the maximum and minimum values during a measurement session. Press and hold for 2 seconds to activate.
• Backlight/Work Light: The meter features a display backlight for low-light conditions and a work light near the clamp jaw.

6.2 Measuring AC/DC Current (Clamp Function)

1. Rotate the dial to the 'A~' (AC Current) or 'A=' (DC Current) position.
2. Open the clamp jaw by pressing the trigger.
3. Place the clamp around a single conductor (not a cable containing multiple conductors) of the circuit you wish to measure.
4. Ensure the jaw is fully closed.
5. Read the current value on the display.

Example of using the clamp meter to measure frequency from an electrical outlet.

6.3 Measuring AC/DC Voltage

1. Insert the red test lead into the 'VΩHz' input terminal and the black test lead into the 'COM' terminal.
2. Rotate the dial to the 'V~' (AC Voltage) or 'V=' (DC Voltage) position.
3. Connect the test leads across the circuit or component to be measured.
4. Read the voltage value on the display.

6.4 Measuring Resistance, Continuity, Diode, and Capacitance

1. Insert the red test lead into the 'VΩHz' input terminal and the black test lead into the 'COM' terminal.
2. Rotate the dial to the 'Ω' (Resistance/Continuity/Diode/Capacitance) position.
3. Press the 'FUNC' button to cycle through Resistance (Ω), Continuity (Buzzer icon), Diode (Diode icon), and Capacitance (F).
4. Connect the test leads to the component. For resistance and capacitance, ensure the component is de-energized.
5. Read the measurement on the display. For continuity, the buzzer will sound if resistance is below 50±20Ω.

7. Specifications

Detailed measurement ranges, resolutions, and accuracies for the MASTECH MS2138.

8. Maintenance

8.1 Cleaning

Wipe the meter with a damp cloth and mild detergent. Do not use abrasives or solvents. Keep the input terminals free of dirt and moisture.

8.2 Battery Replacement

When the low battery indicator appears on the display, replace the batteries as described in the 'Battery Installation' section (5.1). Always use three new 1.5V AAA batteries.

8.3 Storage

If the meter is not to be used for an extended period, remove the batteries to prevent leakage and damage. Store the meter in a cool, dry place, away from direct sunlight and extreme temperatures.

9. Troubleshooting

10. User Tips

No specific user tips were available from reviews or Q&A for this product at this time. However, general tips for clamp meter users include:

• Always ensure the clamp jaw is fully closed for accurate current measurements.
• When measuring current, clamp around only one conductor. Clamping around a multi-conductor cable will result in a zero reading as the magnetic fields cancel each other out.
• For stable readings, especially in noisy electrical environments, use the 'HOLD' function to capture a momentary value.
• The 'REL' function is useful for nulling out test lead resistance when measuring small resistances or for comparing measurements against a known baseline.

11. Warranty & Support

The MASTECH MS2138 Digital Clamp Meter is designed and manufactured to high-quality standards and is CE certified, indicating compliance with European safety, health, and environmental protection requirements.

For any technical support or warranty inquiries, please refer to the contact information provided with your purchase documentation or contact your local MasTech distributor.