Fluke 381

Understanding the RF Symbol

Presence of RF Interference: The Fluke 381 is designed to pick up on electromagnetic signals, which includes RF signals. When it detects a strong RF source, the "RF" symbol appears to warn you that your readings may be inaccurate.

Common Sources: Some common sources of strong RF signals include:

Radio and television transmitters

Cell phone towers

Microwave ovens

Welding equipment

Motors and other industrial machinery

Troubleshooting

Identify the Source: Try to figure out where the RF signal is coming from. Move the meter around to see if the signal gets stronger or weaker in certain areas.

Increase Distance: If possible, move the meter away from the suspected RF source. The intensity of RF signals diminishes with distance, and increasing the space between the meter and the source should lessen its effect.

Shielding: If you can't move away from the source, try shielding the meter. This could involve using metallic foil or specialized RF shielding material designed to block electromagnetic interference.

Frequency Filtering (if available): Some advanced meters might have the option to filter out specific frequency ranges. Check your Fluke 381 manual to see if this feature exists and how to use it.

Important Notes:

The RF symbol itself doesn't mean there's an error with your meter. It's a warning that the readings might be compromised.

If you can't eliminate the RF interference and you need accurate measurements, you may have to use a different meter that's less susceptible to RF, or consider taking your measurements in a location with lower RF noise.

For further assistance, you might want to:

Consult the Fluke 381 Manual: Look for a section on troubleshooting RF interference. You can likely find it online if you don't have the physical manual. (https://www.cedesa.com.mx/pdf/fluke/fluke-381_user_manual.pdf)

Contact Fluke Support: They can provide more specific guidance for your meter and any potential solutions.

Let me know if you have other questions.