MESTEK DM92S/B Digital Pen Multimeter User Manual

1. Introduction

The MESTEK DM92S/B is a compact, pen-type digital multimeter designed for high-precision electrical measurements. It features True RMS technology and a 6000-count display, making it suitable for a wide range of applications from household electrical checks to professional diagnostics. This manual provides essential information for the safe and effective use of your multimeter.

Figure 1: MESTEK DM92S/B Digital Pen Multimeter and its key functions.

2. Safety Information

Always observe basic safety precautions when using this multimeter to reduce the risk of fire, electric shock, or personal injury.

• Read and understand all instructions in this manual before use.
• Do not exceed the maximum input values specified for each function.
• Do not use the meter if it or the test leads appear damaged.
• Exercise extreme caution when working with voltages above 30V AC RMS, 42V peak, or 60V DC. These voltages pose a shock hazard.
• Keep your fingers behind the finger guards on the test probes during use.
• Remove test leads from the circuit before changing functions.
• Replace the battery immediately when the low battery indicator appears.
• Do not operate the meter in explosive gas, vapor, or dust environments.
• Ensure the battery compartment is securely closed before operation.

3. Package Contents

Verify that all items listed below are included in your package:

Figure 2: Package Contents.

1. Packing bag
2. Multimeter (DM92S or DM92B)
3. Black test lead
4. Alligator clip
5. User Manual
6. Certificate
7. Packing box

Note: This product does not include batteries. Please prepare 2x 1.5V AAA batteries for operation.

4. Product Overview

Familiarize yourself with the components and controls of your MESTEK pen multimeter:

Figure 3: Multimeter Face Plate and Technical Parameters.

• Red Test Pen: Main probe for measurements.
• Black Test Lead: Connects to the COM jack for common ground.
• Function Indicator: Displays the current measurement mode.
• Switch: Power on/off and function selection.
• AC Frequency Measurement Button (Hz): Activates frequency measurement.
• Display Screen: LCD high-definition digital display for readings.
• Flashlight: Provides illumination for dark environments.
• Illumination Backlight Switch: Controls the screen backlight.
• Gear Selection (Rotary Switch): Selects different measurement functions.
• Screen Inverted: Flips the display orientation.
• Select Button (SEL): Toggles between sub-functions within a mode (e.g., AC/DC).
• Test Lead Jack (COM): Connection point for the black test lead.

5. Setup

5.1. Battery Installation

The multimeter requires two 1.5V AAA batteries (not included). To install:

1. Locate the battery compartment on the back of the multimeter.
2. Open the battery cover.
3. Insert two AAA batteries, ensuring correct polarity (+/-).
4. Close the battery cover securely.

5.2. Connecting Test Leads

Connect the black test lead to the 'COM' jack on the multimeter. The red test pen is integrated. For certain measurements, the alligator clip can be attached to the black test lead.

6. Operating Instructions

The MESTEK DM92S/B offers various measurement functions. The DM92S model features smart measurement, while the DM92B has an auto-ranging function. Both models include Firewire detection, capacitance measurement, and a 180-degree flip screen.

6.1. Power On/Off and Auto Shut-down

Press the power button to turn the multimeter on or off. To conserve battery life, the multimeter will automatically shut down if not used within 15 minutes.

Figure 4: Low power consumption mode with 15-minute auto shut-down.

6.2. Measurement Functions

Use the rotary switch to select the desired measurement function. The 'SEL' button can be used to switch between AC/DC or other sub-modes where applicable.

Figure 5: Common Multimeter Functions.

6.2.1. AC/DC Voltage Measurement

Turn the rotary switch to the voltage (V) position. Use the red test pen and black test lead to contact the circuit points. The display will show the voltage reading. The DM92S/B can measure AC voltage from 6V to 600V and DC voltage from 600mV to 600V.

Figure 6: Application scenarios for AC and DC voltage measurement.

6.2.2. Resistance Measurement

Turn the rotary switch to the resistance (Ω) position. Connect the red test pen and black test lead across the component to measure its resistance. The range is 600Ω to 60MΩ.

Figure 7: Detailed measurement examples including resistance.

6.2.3. Capacitance Measurement

Turn the rotary switch to the capacitance (F) position. Connect the test leads across the capacitor. The multimeter can measure capacitance from 6nF to 60mF.

Figure 8: Detailed measurement examples including capacitance.

6.2.4. Frequency Measurement

Press the 'Hz' button to activate frequency measurement. The multimeter supports frequency measurements from 40Hz to 9.9MHz.

6.2.5. NCV (Non-Contact Voltage) Detection

Adjust the rotary switch to the NCV position. Bring the tip of the multimeter close to the circuit or wire. The device will emit different beeps and visual indicators according to the detected voltage level.

Figure 9: Non-contact voltage detection in action.

6.2.6. Buzzer/Diode Test

The multimeter features automatic recognition for buzzer (continuity) and diode tests. Select the appropriate mode with the rotary switch. For diode measurement, turn to the diode position, and the positive and negative electrodes can be contacted to measure.

Figure 10: Diode measurement example.

6.2.7. Zero/Fire Wire Detection (LIVE)

This function helps identify live wires. Refer to the specific instructions in the full manual for safe usage.

6.2.8. Flashlight and Backlight

The device is equipped with a flashlight for working in dimly lit areas and a screen backlight for improved visibility of the display.

Figure 11: LCD high-definition digital display with backlight and flashlight function.

6.2.9. Data Retention (HOLD)

Press the 'HOLD' button to freeze the current reading on the display. Press it again to release.

7. Maintenance

7.1. Cleaning

Wipe the case with a damp cloth and mild detergent. Do not use abrasives or solvents. Keep the test leads clean and free of debris.

7.2. Storage

When not in use, store the multimeter in its packing bag in a dry, cool place. For prolonged storage, remove the batteries to prevent leakage.

7.3. Battery Replacement

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

8. Troubleshooting

• No Display: Check if the batteries are correctly installed and have sufficient charge. Replace if necessary.
• Inaccurate Readings: Ensure the test leads are properly connected and the correct measurement function is selected. Check for external interference.
• No NCV Detection: Verify the multimeter is in NCV mode and is brought close enough to the live wire.
• Multimeter Does Not Turn On: Ensure batteries are installed and charged. If the issue persists, contact support.

9. Specifications

The following table details the technical specifications for the MESTEK DM92S and DM92B models:

Figure 12: Counting Parameters (Specifications).

10. User Tips

• Portability: The pen-shaped design allows for easy one-handed operation and portability, making it convenient for on-the-go measurements.
• Dark Environments: Utilize the built-in flashlight and screen backlight for clear readings and safe operation in low-light conditions.
• Battery Life: Take advantage of the automatic shut-down feature (after 15 minutes of inactivity) to prolong battery life.
• Smart vs. Auto Range: Understand the difference between the DM92S (Smart measurement) and DM92B (Auto range) models to select the one best suited for your specific needs. Smart measurement simplifies operation by automatically identifying the measurement type.

11. Warranty and Support

This MESTEK product is covered by a manufacturer's warranty. For warranty claims, technical support, or service inquiries, please refer to the contact information provided with your purchase or visit the official MESTEK website. Keep your purchase receipt as proof of purchase.