How to Use Your Fluke 101 Multimeter to Test Frequency

Did you know your Fluke 101 multimeter can measure not only voltage and resistance but also frequency?

Whether you’re checking an outlet, inverter, or generator output, understanding frequency is crucial—especially when working with AC power systems around the world.

What Is Frequency?

Frequency refers to how many times an electrical signal repeats its pattern per second. It's measured in Hertz (Hz).

For example:

• North America: 60 Hz
• Europe & most of Asia: 50 Hz

That simply means the AC sine wave in those regions repeats 60 or 50 times per second.

The frequency is determined by the speed of the power generator used by your local electrical grid.

⚠️ Safety First

Before working with live circuits, remember:

⚡ Electricity is dangerous and can be fatal.
Only qualified and competent individuals should perform electrical measurements.

Even if you're just measuring frequency, always take proper precautions:

• Turn off power before connecting or disconnecting test leads
• Do not touch probe tips during testing
• Wear rubber boots and gloves if available
• Avoid grounded surfaces during measurement

How to Measure Frequency with the Fluke 101

✅ Step-by-step:

• step1: Insert the probes:
  Black lead → COM terminal
  Red lead → V terminal
• step2: Turn the dial to the frequency mode (Hz):
  On the Fluke 101, frequency has its own dedicated position on the dial.
  Simply rotate the selector to the Hz symbol.
• step3: Connect the probes to the live AC source (e.g., wall outlet or AC test point).
  ⚠️ Always connect with power turned off initially.
• step4: Turn the power on, and your Fluke 101 will display the frequency reading in Hertz (Hz).
  • You’ll typically see 50.0 Hz or 60.0 Hz, depending on your location.
• step5: Turn off the power before removing the probes.

Why Use Frequency Mode?

Testing frequency is especially useful when:

• Working with generators, UPS systems, or inverters
• Verifying the output of variable frequency drives (VFDs)
• Ensuring your device is operating at the correct grid frequency

If you notice fluctuations in power or equipment behaving oddly, frequency testing can help isolate the problem.

Summary: Using Fluke 101 for Frequency