Mastech MY64 Digital Multimeter User Manual

1. Introduction

Thank you for choosing the Mastech MY64 Full Featured 32-Range Digital Multimeter. This manual provides essential information for the safe and effective operation, maintenance, and troubleshooting of your device. Please read this manual thoroughly before use and retain it for future reference.

2. Safety Information

Always observe safety precautions when using any electrical testing equipment. Failure to do so may result in injury or damage to the multimeter or equipment under test.

• Do not exceed the maximum input limits for any function.
• Use extreme caution when working with voltages above 60V DC or 30V AC RMS.
• Ensure the function switch is in the correct position for the measurement being performed.
• Inspect test leads for damage before each use. Do not use if insulation is compromised.
• Do not operate the multimeter if it appears damaged or is not functioning properly.
• Always disconnect power to the circuit and discharge high-voltage capacitors before making resistance, continuity, diode, or capacitance measurements.
• Replace the battery when the low battery indicator appears to ensure accurate readings.

The MY64 is designed to meet IEC61010-1 safety standards.

3. Product Overview

The Mastech MY64 is a versatile digital multimeter offering 32 measurement ranges for various electrical parameters. It features a large LCD display for easy reading, an auto power-off function to conserve battery life, and a low battery indication.

Figure 3.1: Front view of the Mastech MY64 Digital Multimeter, showing the display, rotary switch, function buttons, and input jacks.

Key Features:

• 32-Range Fully Featured DMM
• Auto Power off function
• Low Battery Indication
• Tilt Back Stand with Test Leads Holder

4. Setup

4.1. Battery Installation

The MY64 multimeter is powered by a 9V battery (NEDA 1604 or 6F22 type). To install or replace the battery:

1. Ensure the multimeter is turned OFF and all test leads are disconnected.
2. Locate the battery compartment cover on the rear of the unit.
3. Remove the screw securing the cover and lift it off.
4. Connect the 9V battery to the battery snap connector, observing correct polarity.
5. Place the battery into the compartment and replace the cover, securing it with the screw.

4.2. Test Lead Connection

Connect the test leads to the appropriate input jacks based on the measurement function:

• Insert the black test lead into the COM (Common) jack.
• For voltage, resistance, frequency, capacitance, diode, and continuity measurements, insert the red test lead into the VΩHz jack.
• For current measurements up to 200mA, insert the red test lead into the mA jack.
• For current measurements up to 20A, insert the red test lead into the 20A jack.

5. Operating Instructions

Before taking any measurement, ensure the multimeter is set to the correct function and range. If the value to be measured is unknown, start with the highest range and work downwards.

5.1. Powering On/Off

To turn the multimeter ON, rotate the central function switch from the "OFF" position to any desired measurement function. To turn it OFF, rotate the switch back to the "OFF" position. The multimeter also features an Auto Power Off function to conserve battery life, which will activate after approximately 15 minutes of inactivity.

5.2. Data Hold Function

Press the HOLD button to freeze the current reading on the display. Press it again to release the hold and resume live readings.

5.3. DC Voltage Measurement (V–)

1. Connect the red test lead to the VΩHz jack and the black test lead to the COM jack.
2. Set the rotary switch to the desired DC Voltage range (e.g., 200m, 2, 20, 200, 1000V).
3. Connect the test leads in parallel to the circuit or component under test.
4. Read the voltage value on the display.

5.4. AC Voltage Measurement (V~)

1. Connect the red test lead to the VΩHz jack and the black test lead to the COM jack.
2. Set the rotary switch to the desired AC Voltage range (e.g., 200, 750V).
3. Connect the test leads in parallel to the AC source or component.
4. Read the voltage value on the display.

5.5. DC Current Measurement (A–)

1. Disconnect power to the circuit.
2. For measurements up to 200mA, connect the red test lead to the mA jack. For measurements up to 20A, connect the red test lead to the 20A jack. Connect the black test lead to the COM jack.
3. Set the rotary switch to the desired DC Current range (e.g., 2m, 20m, 200m, 20A).
4. Open the circuit where current is to be measured and connect the multimeter in series.
5. Apply power to the circuit and read the current value on the display.

5.6. Resistance Measurement (Ω)

1. Ensure the circuit is de-energized and all capacitors are discharged.
2. Connect the red test lead to the VΩHz jack and the black test lead to the COM jack.
3. Set the rotary switch to the desired Resistance range (e.g., 200, 2k, 20k, 200k, 2M, 20M, 200MΩ).
4. Connect the test leads across the component to be measured.
5. Read the resistance value on the display.

5.7. Diode Test (→|→)

1. Ensure the circuit is de-energized and all capacitors are discharged.
2. Connect the red test lead to the VΩHz jack and the black test lead to the COM jack.
3. Set the rotary switch to the Diode Test position.
4. Connect the red test lead to the anode and the black test lead to the cathode of the diode. The display will show the forward voltage drop.
5. Reverse the leads. The display should show "OL" (Overload) for a good diode.

5.8. Continuity Test (⦙)

1. Ensure the circuit is de-energized and all capacitors are discharged.
2. Connect the red test lead to the VΩHz jack and the black test lead to the COM jack.
3. Set the rotary switch to the Continuity Test position.
4. Connect the test leads across the circuit or component.
5. If continuity exists (resistance below approximately 50Ω), the built-in buzzer will sound. The display will show the resistance value.

5.9. Capacitance Measurement (F)

1. Ensure the capacitor is fully discharged before testing.
2. Connect the red test lead to the VΩHz jack and the black test lead to the COM jack.
3. Set the rotary switch to the desired Capacitance range (e.g., 20nF, 200nF, 2µF, 20µF, 200µF).
4. Connect the test leads across the capacitor. Observe polarity for electrolytic capacitors.
5. Read the capacitance value on the display.

5.10. Temperature Measurement (Temp)

The MY64 supports temperature measurement, typically requiring a K-type thermocouple (not included with all models). Refer to your specific package contents.

1. Connect the temperature probe to the appropriate input jacks (usually the VΩHz and COM jacks, or dedicated temperature jacks if present).
2. Set the rotary switch to the Temp position.
3. Place the probe tip on or near the object whose temperature is to be measured.
4. Read the temperature value on the display.

5.11. hFE Measurement (Transistor Test)

The MY64 includes a socket for testing the hFE (DC current gain) of NPN and PNP transistors.

1. Set the rotary switch to the hFE position.
2. Identify the Emitter (E), Base (B), and Collector (C) leads of the transistor.
3. Insert the transistor leads into the corresponding holes in the NPN or PNP socket on the multimeter.
4. Read the hFE value on the display.

6. Maintenance

6.1. Cleaning

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

6.2. Battery Replacement

Refer to Section 4.1 for instructions on replacing the 9V battery when the low battery indicator appears on the display.

6.3. Fuse Replacement

The MY64 features a self-resetting fuse for the 20A current range, indicated by "SELF-RESETTING" on the front panel. The lower current ranges (mA) are unfused. If the 20A range stops functioning, disconnect the multimeter from all circuits and allow a few minutes for the fuse to reset. If the issue persists, contact customer support.

7. Troubleshooting

8. Specifications

9. Warranty and Support

The Mastech MY64 Digital Multimeter comes with a 1 Year Manufacturer's Warranty. For warranty claims or technical support, please contact Tekpower customer service. Additionally, a 30 Day Money Back Guarantee is offered.

For further assistance, please visit the Tekpower Store on Amazon.