FLUKE 15B MAX Digital Multimeter User Manual

1. Introduction

The FLUKE 15B MAX is an economical, multi-functional digital multimeter designed for high-precision electrical measurements. It features fully automatic ranging, making it user-friendly for various applications. This manual provides essential information for the safe and effective operation, maintenance, and troubleshooting of your FLUKE 15B MAX multimeter.

Figure 1: FLUKE 15B MAX Digital Multimeter with included test leads.

Key Features:

• Input Alert™: A safety feature designed to reduce efficiency loss and potential hazards from incorrect fuse handling. It provides an alarm effect through flashing lights, especially useful in noisy or dark environments.
• High-Precision Measurements: Capable of accurate readings for voltage, current, resistance, and capacitance.
• Automatic Ranging: Simplifies operation by automatically selecting the correct measurement range.
• Compact Design: Ergonomic and portable for on-site testing.
• Optional 1mm Extra Tip Test Pen: Available with 15B MAX-02 and KIT models, this thinner tip allows for precise measurements on circuit board device pins, helping to avoid short circuits in small spaces.

2. Safety Information

WARNING: To avoid possible electric shock, fire, or personal injury, read all safety information before you use the product. Always use the meter as specified in this manual; otherwise, the protection provided by the meter might be impaired.

• Always disconnect power to the circuit under test before connecting or disconnecting test leads.
• Do not apply more than the rated voltage, as marked on the meter, between terminals or between any terminal and earth ground.
• Use caution with voltages above 30 V AC RMS, 42 V peak, or 60 V DC. These voltages pose a shock hazard.
• Use the correct terminals, function, and range for all measurements.
• Check the continuity of the test leads before use. Do not use damaged test leads.
• Do not operate the meter if it is damaged or if the case is open.
• Do not operate the meter around explosive gas, vapor, or dust.
• Adhere to local and national safety codes. Individual protective equipment must be used to prevent shock and arc blast injury where hazardous live conductors are exposed.
• The meter is rated for CAT III 600V and CAT II 1000V. Ensure your measurement category matches the meter's rating.

3. Package Contents

The contents of your FLUKE 15B MAX package may vary depending on the specific model purchased. Please verify that all items are present upon unboxing.

Typical Contents by Model:

• FLUKE 15B MAX-01 Digital Multimeter:
  • FLUKE 15B MAX Digital Multimeter Unit
  • TL75 Test Probe with two protective caps
  • 2 AA Batteries (Note: Batteries may not be included due to shipping regulations in some regions.)
  • User Manual
• FLUKE 15B MAX-02 Digital Multimeter:
  • FLUKE 15B MAX Digital Multimeter Unit
  • TL31 Special Tip Pen with two protective caps
  • 2 AA Batteries (Note: Batteries may not be included due to shipping regulations in some regions.)
  • User Manual
• FLUKE 15B MAX KIT Digital Multimeter:
  • FLUKE 15B MAX Digital Multimeter Unit
  • TL75 Test Probe with two protective caps
  • TL31 Special Tip Pen with two protective caps
  • 2 AA Batteries (Note: Batteries may not be included due to shipping regulations in some regions.)
  • User Manual

4. Setup

4.1. Battery Installation

1. Ensure the multimeter is turned OFF.
2. Locate the battery compartment cover on the back of the unit.
3. Use a screwdriver to open the battery compartment.
4. Insert two AA batteries, observing the correct polarity (+ and -) as indicated inside the compartment.
5. Replace the battery compartment cover and secure it with the screw.

4.2. Connecting Test Leads

Figure 2: Input jacks for test leads on the FLUKE 15B MAX.

1. Insert the black test lead into the "COM" (common) input jack.
2. For most voltage, resistance, capacitance, and diode measurements, insert the red test lead into the "VΩ" input jack.
3. For current measurements (mA/µA), insert the red test lead into the "mAµA" input jack.
4. For high current measurements (up to 10A), insert the red test lead into the "A" input jack.
5. Ensure test leads are fully inserted and securely connected.

5. Operating Modes

The FLUKE 15B MAX features a rotary dial to select different measurement functions. The meter defaults to auto-ranging for most functions, simplifying operation.

Figure 3: Front view of the multimeter showing the display, buttons, and rotary dial.

5.1. Function Selection (Rotary Dial)

• OFF: Turns the multimeter off.
• V~ (AC Voltage): Measures alternating current voltage.
• V- (DC Voltage): Measures direct current voltage.
• mV~ (AC Millivolts): Measures small AC voltages.
• Ω (Resistance): Measures electrical resistance.
• ))) (Continuity): Tests for continuity (a complete circuit). The meter will beep if continuity is detected.
• -|- (Capacitance): Measures capacitance.
• A~ (AC Amps): Measures alternating current.
• A- (DC Amps): Measures direct current.
• mA~ (AC Milliamps): Measures small alternating currents.
• mA- (DC Milliamps): Measures small direct currents.
• µA~ (AC Microamps): Measures very small alternating currents.
• µA- (DC Microamps): Measures very small direct currents.

5.2. Button Functions

• HOLD: Freezes the current reading on the display. Press again to release.
• RANGE: Switches between auto-ranging and manual ranging. In manual ranging, press repeatedly to cycle through available ranges.
• Backlight Button (Sun icon): Activates the display backlight for better visibility in low-light conditions.
• Yellow Button (Function Select): For functions with multiple modes (e.g., AC/DC voltage, continuity/diode), press this button to toggle between modes.

5.3. Input Alert™ Feature

The Input Alert™ feature provides an audible and visual warning (flashing lights) if the test leads are incorrectly connected for the selected function. This helps prevent damage to the meter and potential hazards. Always ensure leads are in the correct jacks before making a measurement.

5.4. Using the 1mm Extra Tip Test Pen (for 15B MAX-02 and KIT models)

For precise measurements on small components or circuit boards, replace the standard test probe with the 1mm extra tip test pen. Its fine tip allows for accurate contact with individual pins and traces, minimizing the risk of short circuits.

6. Maintenance

6.1. Cleaning

Wipe the case with a damp cloth and mild detergent. Do not use abrasives or solvents. Clean the terminals periodically with a cotton swab and alcohol to ensure good contact.

6.2. Battery Replacement

When the battery indicator appears on the display, replace the batteries as described in the "Battery Installation" section (4.1). Always use two new AA batteries.

6.3. Fuse Replacement

WARNING: To avoid injury or damage to the meter, replace blown fuses only with fuses of the specified type and rating.

If the meter fails to measure current, the fuse may be blown. Refer to the full user manual for detailed instructions on accessing and replacing the fuses. Typically, the meter uses two fuses: one for the mA/µA range and one for the A range.

6.4. Storage

If the meter is not 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.

7. Troubleshooting

8. Specifications

9. User Tips

Here are some general tips to enhance your experience and ensure safe operation of your digital multimeter:

• Always Start High: When measuring an unknown voltage or current, always start with the highest range setting and work your way down. This prevents overloading the meter.
• Check Test Leads: Before each use, visually inspect your test leads for any signs of damage (cracks, frayed insulation). Replace them immediately if damaged.
• Secure Connections: Ensure test leads are firmly inserted into the correct input jacks and make good contact with the circuit points being measured.
• Use the Kickstand: The integrated kickstand allows for hands-free operation, improving safety and convenience.


Figure 4: Multimeter shown with its kickstand for convenient viewing.

• Understand "OL": An "OL" (Overload) reading typically means the value being measured is higher than the selected range or the meter's maximum capacity. It can also indicate an open circuit in resistance or continuity tests.
• Battery Life: To conserve battery life, remember to turn off the multimeter when not in use.

10. Warranty and Support

For specific warranty information, please refer to the warranty card included with your product or the purchase documentation. In case of technical issues, questions, or the need for repair services, please contact the seller or the official FLUKE customer support in your region. Keep your proof of purchase for warranty claims.