fluke 179 user manual
Fluke 179 User Manual: A Comprehensive Guide
This manual details the Fluke 175, 177, and 179 True-RMS multimeters, offering a 6000-count display and bar graph for precise measurements.

The Fluke 179 is a robust, handheld True-RMS multimeter designed for electrical professionals needing reliable and accurate measurements. This manual serves as a comprehensive guide for operating the Fluke 179, covering safety precautions, detailed operating instructions, and troubleshooting tips. It applies equally to the Fluke 175 and 177 models within the 170 Series.
Understanding this manual ensures optimal performance and longevity of your meter, enabling confident diagnosis and repair in various electrical applications. All illustrations depict the Fluke 179 model.
Key Features of the Fluke 179 DMM

The Fluke 179 boasts True-RMS accuracy for AC voltage and current measurements, ensuring reliable readings even with complex waveforms. It features a large 6000-count digital display and a bright analog bar graph for easy visualization of results.
Additional features include continuity testing, diode test, resistance measurement, and temperature measurement when paired with the 80BK probe. This DMM meets IEC 61010 Category III and IV safety standards, providing a safe and dependable tool for professionals.
Safety Precautions
To avoid injury or damage, always exercise caution when working with electrical circuits. Never attempt current measurements in circuits where the open-circuit voltage exceeds the meter’s rating. Before testing, verify the condition of the meter’s fuses.
This multimeter complies with IEC 61010 Categories III and IV. Always disconnect test leads before changing batteries. Follow all general safety rules and specific warnings related to current measurement to ensure safe operation.
General Safety Rules
Always inspect test leads for damage before use, replacing any worn or cracked leads immediately. Avoid applying voltage beyond the meter’s specified limits. Do not use the meter in hazardous environments. Disconnect all power sources before opening the meter for fuse replacement or battery changes.
Ensure a safe working environment, free from flammable materials. Never operate the meter with a damaged case. Follow established safety procedures for electrical work.
Specific Warnings for Current Measurement
Never attempt in-circuit current measurements with open-circuit potential exceeding the meter’s rating; damage or injury may occur. Always check the meter’s fuses before measuring current. Ensure the test leads are properly connected to the correct terminals (COM and 10A or VΩmA).
Be cautious when measuring high currents, as excessive heat can be generated. Avoid touching exposed conductors during current measurements.
Understanding the Meter Display
The Fluke 179 features a 6000-count, 3 3/4-digit digital display providing clear and precise readings of measured values. Alongside the numerical display, an analog bar graph visually represents the signal strength, offering a quick reference for changing values.
The display also incorporates function indicators, range selectors, and other symbols to convey measurement context and status information to the user.
6000-Count Digital Display
The primary readout on the Fluke 179 is a large, high-contrast 6000-count digital display. This means the meter can represent values up to 6000, providing a high degree of resolution for accurate measurements. The 3 3/4-digit format ensures clear presentation of numerical results.
This display is crucial for obtaining precise readings in various measurement modes, including voltage, current, and resistance.
Analog Bar Graph
Complementing the digital display, the Fluke 179 features a dynamic analog bar graph. This visual representation provides a real-time trend of the measured signal, allowing users to quickly observe fluctuations and rate of change. The bar graph enhances usability, especially when monitoring signals that are rapidly varying.
It offers a quick visual confirmation of signal strength and helps identify intermittent issues.
Operating Instructions
To begin, ensure the test leads are securely connected to the appropriate terminals. Press the yellow power button to turn the meter on; it will default to DC Voltage measurement. Rotate the rotary dial to select the desired measurement function – voltage, current, resistance, continuity, or diode test.
Always verify fuse integrity before testing, and refer to the manual for specific function settings and ranges.
Powering On and Off
The Fluke 179 is activated by pressing the yellow power button located on the front panel. Upon powering on, the meter performs a self-test, briefly displaying all digits. To conserve battery life, the meter automatically powers off after a period of inactivity. This auto-off feature can be disabled within the meter’s settings.
Ensure the battery is adequately charged for accurate readings; low battery indication appears on the display.

Selecting Measurement Functions
The rotary dial on the Fluke 179 is used to select the desired measurement function; Options include DC and AC Voltage, DC and AC Current, Resistance, Continuity, Diode Test, and Temperature (with the optional 80BK probe). Rotate the dial to align with the appropriate symbol for the measurement you intend to perform.

After selection, connect the test leads to the correct input terminals for accurate results.
Measurement Capabilities
The Fluke 179 offers a versatile range of measurement capabilities. It accurately measures DC and AC Voltage and Current, alongside Resistance, Continuity, and performs Diode Tests. With the optional 80BK temperature probe, it extends functionality to include temperature measurements.
This DMM provides True-RMS readings for AC signals, ensuring precision. It’s designed for various electrical troubleshooting and maintenance applications.
DC Voltage Measurement
To measure DC Voltage, connect the test leads appropriately: black to COM and red to VΩmA. Select the DC Voltage (VDC) range on the rotary dial, starting with the highest range and decreasing for better resolution. Apply the probes to the circuit, observing the polarity. The Fluke 179 displays the DC voltage value, with a maximum input of 600V DC.
Ensure proper lead connection for accurate readings.
AC Voltage Measurement
For AC Voltage measurements, connect the black test lead to the COM terminal and the red lead to the VΩmA terminal. Rotate the dial to select the AC Voltage (VAC) range, beginning with the highest setting and adjusting downwards for optimal precision. Apply the probes across the circuit under test, and the Fluke 179 will display the AC voltage value.
Maximum input is 600V AC; ensure secure connections.
DC Current Measurement
To measure DC Current, first, ensure the circuit is broken and the test leads are connected correctly. The black lead goes to the COM terminal, and the red lead to the 10A or VΩmA terminal, depending on the expected current level. Select the DCA range on the rotary dial, starting with the highest range.
Caution: Never attempt in-circuit current measurements with high open-circuit potential.
AC Current Measurement
For AC Current measurements, similarly break the circuit and connect the test leads – black to COM, and red to either the 10A or VΩmA terminal, based on anticipated current. Select the ACA range on the dial, beginning with the highest setting for safety.
Important: Always verify the meter’s fuses before testing, as current measurements can easily blow them. Avoid in-circuit measurements with high voltage potential.
Resistance Measurement
To measure resistance, ensure the circuit is de-energized – power off and disconnect. Connect the test leads; black to COM and red to VΩmA. Select the resistance (Ω) range on the rotary dial, starting with the highest range for safety.
Continuity Testing
Continuity testing verifies electrical connection. Select the continuity function (audible diode symbol) by turning the rotary dial. Connect the test leads to the points you wish to test – black to COM and red to VΩmA.
If the resistance is below approximately 30Ω, the meter beeps, indicating continuity. Ensure the circuit is de-energized before testing. A lack of a beep signifies an open circuit or high resistance.
Diode Test
The diode test function checks the forward voltage drop of a diode. Select the diode test function (diode symbol) using the rotary dial. Connect the red test lead to the anode (positive side) and the black lead to the cathode (negative side) of the diode.
A forward-biased diode will display a voltage drop (typically 0.5V to 0.8V). A reading of “OL” indicates an open circuit, while a reading close to 0V suggests a shorted diode.

Temperature Measurement (with 80BK Probe)
The Fluke 179, when paired with the 80BK Temperature Probe, can accurately measure temperature in Celsius or Fahrenheit. Connect the probe to the meter’s input terminals. Select the temperature function on the rotary dial.

Ensure the probe tip is in good thermal contact with the object being measured. The display will show the temperature reading. Note that accuracy depends on proper probe placement and environmental conditions.
Using the HOLD and AUTO HOLD Functions
The Fluke 179 offers both manual HOLD and convenient AUTO HOLD functions for capturing stable readings. Pressing the HOLD button freezes the displayed value, allowing for easy recording.
AUTO HOLD automatically captures and holds a stable reading after a defined period, ideal for fluctuating signals. This feature simplifies measurement in hard-to-reach or visually obscured locations, ensuring accurate data capture without constant monitoring.

Data Hold Function
The Data Hold function on the Fluke 179 is essential for capturing a stable reading in dynamic environments. Activating this feature freezes the current display value, allowing you to easily record the measurement even if the input signal fluctuates afterward.
To engage Data Hold, simply press the HOLD button. A HOLD icon appears on the display, confirming activation. Pressing HOLD again cancels the function, returning to live readings. This is particularly useful when taking measurements in locations where visual confirmation is difficult.
Auto Hold Function

The Auto Hold feature of the Fluke 179 automatically captures and displays stable readings, simplifying measurement processes. When enabled, the meter continuously monitors the input signal and only displays a value when it stabilizes within a defined tolerance.
To activate Auto Hold, press and hold the HOLD button until the Auto Hold icon appears. This eliminates the need to manually hold fluctuating readings, saving time and ensuring accurate data capture. The meter will disregard unstable signals, presenting only finalized values.

Input Terminals Explained
The Fluke 179 features three key input terminals for versatile measurements: COM (Common), VΩmA, and 10A. The COM terminal serves as the reference point for all measurements, typically connected to the circuit ground or negative potential.
The VΩmA terminal is used for voltage, resistance, and low-current measurements (milliamperes). The 10A terminal is specifically designed for high-current measurements, up to 10 amperes; ensure proper fuse protection when utilizing this terminal.
COM (Common) Terminal
The COM terminal, colored black, functions as the common reference point for all measurements performed with the Fluke 179. It establishes a stable zero potential, crucial for accurate readings. Always connect the COM lead to the circuit ground or the negative side of the power supply.
Proper connection to the COM terminal is fundamental; it ensures a complete circuit and prevents inaccurate or potentially damaging measurements. This terminal is universally used across all measurement functions of the multimeter.
VΩmA Terminal
The VΩmA terminal, typically red, serves as the positive input for voltage, resistance, and low current (mA) measurements on the Fluke 179. It’s the primary connection point for most general-purpose testing scenarios;
When measuring voltage, connect this terminal to the point where you intend to measure the potential difference. For resistance and current, ensure the circuit is properly configured before connecting the lead. Incorrect usage can damage the meter or the circuit under test.
10A Terminal
The 10A terminal, usually red, is specifically designed for measuring high DC and AC currents, up to 10 amperes, on the Fluke 179. It’s crucial to use this terminal only when expecting currents exceeding the VΩmA terminal’s capacity.
Before connecting, always verify the fuse is intact and of the correct rating. Incorrectly using this terminal, or a blown fuse, can lead to inaccurate readings and potential damage to the meter. Never attempt to measure voltage or resistance through this terminal.
Fuse Replacement
Protecting the Fluke 179 requires proper fuse replacement to ensure accurate measurements and prevent damage. Always disconnect test leads and power off the meter before proceeding. Locate the fuse compartment on the rear panel.
Identify the correct fuse type – crucial for safe operation. Use only fuses with the specified voltage and current rating. Carefully remove the old fuse and install the new one, ensuring a snug fit. Incorrect fuse installation can compromise safety and meter functionality.
Identifying the Fuse Type
Correct fuse identification is paramount for safe and accurate operation of the Fluke 179. The meter utilizes different fuse types for various current ranges and protection circuits.
For high-current measurements (10A), a fast-blow fuse is required. Lower current ranges utilize a slow-blow fuse. Refer to the meter’s documentation or the inside of the fuse compartment door for the precise fuse specifications – voltage and current rating are critical. Using the wrong fuse can create a safety hazard!
Replacing the Fuse Safely
Always disconnect test leads and any input signals before replacing a fuse to prevent electrical shock or damage to the meter. Power off the Fluke 179. Locate the fuse compartment on the rear panel and carefully open it using a screwdriver.
Inspect the old fuse to determine the correct replacement. Replace only with a fuse of the exact same type, voltage, and current rating. Never use a wire or other substitute. Reassemble the compartment securely before powering on.
Calibration Information
Maintaining accurate measurements requires periodic calibration of the Fluke 179. The recommended calibration interval is one year, though frequency depends on usage and environmental conditions. Fluke offers calibration services, or qualified third-party labs can perform the procedure.
The Fluke 179 utilizes the RSCAL calibration procedure. This involves specific steps to adjust internal settings for optimal accuracy. Refer to the separate “Calibration Information Manual” for detailed instructions and specifications regarding the calibration process.
RSCAL Calibration Procedure
The RSCAL procedure, detailed in the separate Calibration Information Manual, allows for field calibration of the Fluke 179. It requires specific precision voltage sources and careful adherence to the outlined steps. Begin by accessing the calibration mode through a key sequence on the meter.
Adjust internal potentiometers according to the manual’s instructions, monitoring the display for accurate readings against the known standards. Proper execution ensures the meter meets its published specifications. Caution: Incorrect adjustment can degrade performance.
Troubleshooting Common Issues
If the meter fails to power on, first verify the battery’s condition or the AC adapter’s connection. Check the fuse – a blown fuse is a frequent cause of no-power situations. For incorrect readings, ensure proper test lead connections and the correct measurement function is selected.
Recalibration might be necessary if accuracy is suspect. If problems persist, consult the full user manual or Fluke’s support resources for more advanced troubleshooting steps and potential repair options.
Meter Doesn’t Power On
If the Fluke 179 doesn’t power on, begin by checking the battery’s charge level and ensuring it’s correctly installed. A weak or improperly seated battery is a common culprit. Next, inspect the fuse; a blown fuse will prevent operation. Verify the AC adapter is securely connected if using external power.
If these steps fail, the power switch itself may be faulty, requiring professional repair. Always consult the user manual before attempting any internal checks.
Incorrect Readings
If the Fluke 179 displays incorrect readings, first confirm the selected measurement function and range are appropriate for the circuit being tested. Ensure test leads are firmly connected to the correct terminals and are undamaged. A blown fuse can also cause inaccurate results, so check its condition.
Consider potential external interference or stray magnetic fields. Recalibration may be necessary if issues persist; refer to the calibration section of this manual.
Fluke 179 Specifications
The Fluke 179 is a True-RMS multimeter featuring a 6000-count digital display and analog bar graph. It offers DC Voltage accuracy of ±0.06%, AC Voltage of ±0.7%, and DC Current of ±0.5%. Resistance measurement ranges up to 40 MΩ, with continuity testing providing audible indication.
Temperature measurements are supported with the 80BK probe. The meter operates on 9V batteries and adheres to IEC 61010 safety standards, categorized as III and IV.
Models Included in the 170 Series
The Fluke 170 Series encompasses three high-performance True-RMS multimeters: the Fluke 175, 177, and 179. All models share a common platform, featuring a 6000-count display and a responsive bar graph for visual representation of measurements.
The Fluke 179 distinguishes itself with the inclusion of an 80BK Temperature Probe, expanding its measurement capabilities. The 175 and 177 offer core multimeter functions, providing versatile solutions for various electrical testing needs.
Fluke 175 True RMS DMM
The Fluke 175 is a battery-powered True-RMS multimeter designed for reliable electrical measurements. It features a clear 6000-count digital display and an analog bar graph, providing both numerical and visual readings. This model is part of the 170 Series, sharing core functionalities with the 177 and 179;
Ideal for field service and general-purpose electrical work, the 175 offers essential measurement capabilities without the added temperature probe included with the 179.
Fluke 177 True RMS DMM
The Fluke 177 is a robust, battery-powered True-RMS digital multimeter, engineered for professionals needing dependable performance. Like the 175 and 179, it boasts a 6000-count display and analog bar graph for comprehensive readings. This model is a key component of the versatile 170 Series.
Designed for demanding environments, the 177 provides accurate measurements for a wide range of electrical applications, offering a balance between features and affordability.
Fluke 179 True RMS DMM
The Fluke 179 is a high-performance, battery-powered True-RMS digital multimeter, part of the acclaimed 170 Series. It features a 6000-count display and a bright analog bar graph, providing clear and precise readings for various electrical measurements.
Notably, the 179 is supplied with an 80BK Temperature Probe, expanding its capabilities beyond standard electrical testing, making it ideal for HVAC and process control applications.


























































































