How to Measure Resistance with the Fluke 101 Multimeter

Testing resistors or checking for continuity in a wire? The Fluke 101 multimeter makes it easy to measure resistance—even if you're new to electronics.

In this post, we’ll walk you through what resistance is, how to use your Fluke 101 to measure it, and what the numbers on the screen actually mean.

What Is Resistance?

Resistance is a measure of how much a material resists the flow of electrical current. It's measured in ohms (Ω).

Think of it like water in a pipe:

• A copper wire lets electricity flow easily—just like a wide pipe.
• A resistor restricts the flow—like narrowing the pipe.

• Rubber, on the other hand, blocks the flow almost completely—like a wall.

That’s why we use copper to conduct electricity and rubber insulation to protect ourselves from it.

🔌 How to Set Up the Fluke 101 for Resistance Testing

1. Plug the black lead into the COM terminal.
2. Plug the red lead into the terminal marked with the Ω (ohm) symbol.
3. Turn the dial to the resistance setting (Ω).

Since the Fluke 101 is an auto-ranging multimeter, you don’t have to choose a specific range—it figures it out for you.

Testing a Resistor

To test resistance:

• Touch the probes to both ends of the resistor (direction doesn’t matter).
• The screen will display a number along with a unit:

You can also test:

• Wires (to check continuity)
• Speakers
• Potentiometers
• Other passive components

Important Things to Know

Tolerance matters
Resistors come with a tolerance rating—e.g., 3 kΩ ±1%, which means:

• • It can range between 2970 Ω and 3030 Ω
  • If your multimeter reads somewhere in between, it's perfectly normal.

Temperature affects resistance
The actual reading may shift slightly with heat or cold.

Don't test components in-circuit (unless you isolate them)
If you try to measure a resistor that's part of a powered or connected circuit, you'll get the wrong value.
For example:

• A 2 MΩ resistor might read 2 kΩ if it’s wired in parallel with another component.
• Always remove one leg from the circuit before testing.

What About Manual Range Multimeters?

If you're using a manual-range device:

• Select the range just above the expected value.
  For instance, if you’re testing a 3 kΩ resistor:
• • Skip the 2k setting
  • Choose 20k for an accurate reading.

If the resistor value is too high for your meter (e.g., above 2 MΩ), the display may just show “1”, indicating overrange.

Additional Functions in the Resistance Mode (Ω)

When the dial is turned to the resistance (Ω) position on the Fluke 101 multimeter, you may notice two additional yellow symbols above the dial: a diode symbol and a speaker/buzzer symbol. These indicate that the meter also supports diode testing and continuity testing in this mode.

1. Continuity Test (🔊 Symbol)

• Purpose: To check if there is a complete (low-resistance) path between two points in a circuit.

• How it works: When the probes are placed across a conductive path with very low resistance (typically less than 30–50 ohms), the meter will emit a beep sound.

• Use case: Ideal for checking wires, fuses, switches, and PCB traces.

2. Diode Test (→|— Symbol)

• Purpose: To test diodes, LEDs, and the forward voltage drop across PN junctions.

• How it works: The multimeter applies a small voltage to the component and displays the forward voltage drop (usually between 0.6–0.7V for silicon diodes). If the diode is good, you’ll see a value; if it’s reversed or faulty, it will show “OL” (open loop).

• Use case: Helpful in testing semiconductors and identifying damaged diodes or incorrect polarity.

 Quick Recap

• Use Ω mode on your Fluke 101 to measure resistance.
• Touch the probes to both ends of the component.
• The Fluke 101 auto-ranges—no need to set it manually.
• Watch for correct units: ohms (Ω), kilo-ohms (kΩ), or mega-ohms (MΩ).
• Always test resistors out of circuit for accurate results.