Hioki DT4252 Standard Digital Multimeter User Manual

1. Introduction

This manual provides essential instructions for the safe and effective use of the Hioki DT4252 Standard Digital Multimeter. The DT4252 is a True-RMS digital multimeter designed for general electrical applications, offering measurements for AC/DC voltage, AC/DC current, resistance, continuity, diode, capacitance, and frequency. Please read this manual thoroughly before operation to ensure correct usage and to prevent accidents.

2. Safety Information

Always observe the following safety precautions to prevent electric shock, injury, or damage to the instrument.

• Do not use the multimeter if it appears damaged or if the test leads are damaged.
• Verify the function switch is in the correct position for the measurement being performed.
• Do not exceed the maximum input ratings for any function. The DT4252 is rated for 1000V AC/DC and 10A direct input.
• Use caution when working with voltages above 30V AC RMS, 42V peak, or 60V DC. These voltages pose a shock hazard.
• Always connect the common (COM) test lead first and disconnect it last.
• Ensure your hands are dry and use insulated gloves when necessary.
• Replace batteries promptly when the low battery indicator appears.
• Do not attempt to measure current on a circuit with voltage present without proper precautions and understanding of the circuit.

3. Package Contents

Upon opening the package, verify that all items are present and undamaged:

• Hioki DT4252 Digital Multimeter
• Test Lead Set
• AAA Batteries (x4)
• Instruction Manual (this document)

4. Product Overview

The Hioki DT4252 features a robust design with a clear digital display and intuitive controls.

Figure 1: Front view of the Hioki DT4252 Digital Multimeter with its integrated kickstand extended, showing the display and rotary switch.

Figure 2: Front view of the Hioki DT4252 Digital Multimeter, illustrating the display, function buttons, rotary switch, and input terminals.

4.1. Display

The large LCD shows measurement values, units, and various indicators such as battery status, range, and function modes.

4.2. Function Buttons

• HOLD: Freezes the current display reading. Press again to release.
• MAX/MIN: Records the maximum and minimum values during a measurement. Press to cycle through MAX, MIN, and current reading.
• FILTER: Activates a low-pass filter for stable readings in noisy environments.
• RANGE: Manually selects the measurement range. Press and hold to return to auto-ranging.
• REL (Relative): Measures the difference between the current reading and a stored reference value.
• Backlight Button: Activates the display backlight for improved visibility in low-light conditions.

4.3. Rotary Switch

Used to select the desired measurement function (e.g., V~, V-, A~, A-, Ω, Continuity, Diode, Capacitance, Frequency).

4.4. Input Terminals

• COM: Common terminal for the black test lead.
• V Ω •))) →|← •F Hz: Input terminal for red test lead for voltage, resistance, continuity, diode, capacitance, and frequency measurements.
• A: Input terminal for red test lead for current measurements up to 10A.

5. Setup

5.1. Battery Installation

1. Ensure the multimeter is turned OFF.
2. Locate the battery compartment cover on the rear of the unit.
3. Use a screwdriver to loosen the screw(s) securing the cover.
4. Remove the cover and insert four (4) AAA batteries, observing correct polarity (+/-).
5. Replace the cover and secure it with the screw(s).

5.2. Connecting Test Leads

Insert the test leads into the appropriate input terminals:

• Always connect the black test lead to the COM terminal.
• For voltage, resistance, continuity, diode, capacitance, and frequency measurements, connect the red test lead to the V Ω •))) →|← •F Hz terminal.
• For current measurements (up to 10A), connect the red test lead to the A terminal.

6. Operating Instructions

Before making any measurement, ensure the test leads are correctly connected and the rotary switch is set to the appropriate function.

6.1. Measuring AC/DC Voltage (V~ / V-)

1. Set the rotary switch to V~ for AC voltage or V- for DC voltage.
2. Connect the test leads in parallel across the circuit or component to be measured.
3. Read the voltage value on the display.

6.2. Measuring AC/DC Current (A~ / A-)

WARNING: Never connect the multimeter in parallel across a voltage source when in current measurement mode. This can cause a short circuit and damage the meter or circuit.

1. Turn OFF power to the circuit.
2. Set the rotary switch to A~ for AC current or A- for DC current.
3. Connect the multimeter in series with the circuit, breaking the circuit to insert the meter.
4. Apply power to the circuit.
5. Read the current value on the display.

6.3. Measuring Resistance (Ω)

1. Ensure the circuit or component is de-energized.
2. Set the rotary switch to Ω.
3. Connect the test leads across the component.
4. Read the resistance value on the display.

6.4. Continuity Test (•))) )

1. Ensure the circuit or component is de-energized.
2. Set the rotary switch to •))).
3. Connect the test leads across the component or wire.
4. An audible beep indicates continuity (low resistance). The display will show the resistance value.

6.5. Diode Test (→|←)

1. Ensure the diode is de-energized and isolated from the circuit.
2. Set the rotary switch to →|←.
3. Connect the red lead to the anode and the black lead to the cathode. A forward voltage drop (e.g., 0.5V to 0.8V) should be displayed.
4. Reverse the leads. The display should show OL (Open Loop) for a good diode.

6.6. Capacitance Measurement (F)

1. Ensure the capacitor is fully discharged before testing.
2. Set the rotary switch to F.
3. Connect the test leads across the capacitor terminals.
4. Read the capacitance value on the display.

6.7. Frequency Measurement (Hz)

1. Set the rotary switch to Hz.
2. Connect the test leads across the signal source.
3. Read the frequency value on the display.

7. Maintenance

7.1. Cleaning

Wipe the case with a damp cloth and mild detergent. Do not use abrasives or solvents. Ensure the meter is completely dry before use.

7.2. Battery Replacement

When the low battery indicator appears on the display, replace the batteries as described in Section 5.1. Use only new AAA batteries of the same type.

7.3. Fuse Replacement

If the current measurement function fails, the fuse may need replacement. The DT4252 uses a 10A fused input. Refer to the detailed service manual for fuse replacement procedures, or contact qualified service personnel.

8. Troubleshooting

If the multimeter does not operate correctly, check the following common issues:

• No Display: Check battery installation and charge level. Replace batteries if necessary.
• Incorrect Readings: Ensure the function switch is set correctly for the measurement type. Verify test lead connections. Check for damaged test leads.
• "OL" (Overload) Display: The measured value exceeds the selected range. Switch to a higher range or ensure the input is within the meter's specifications.
• Current Measurement Not Working: Check the 10A fuse. If blown, it needs replacement by qualified personnel.

For persistent issues, contact Hioki customer support.

9. Specifications

10. Warranty and Support

The Hioki DT4252 Digital Multimeter is covered by a manufacturer's warranty against defects in materials and workmanship. For specific warranty terms, duration, and to obtain technical support or service, please refer to the warranty card included with your product or visit the official Hioki website. Keep your purchase receipt as proof of purchase.