What Is a Meter Burden?

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Meter burden is the load a meter puts on the circuit it measures. Every meter draws a small amount of current through its input, and that current can pull the circuit’s voltage down or make a faint voltage look present when it is not. The Fluke article we opened does not use the word “burden.” It describes the same effect as input impedance and loading, and this post uses “burden” for that effect.

Quick answer

• Burden is the load the meter’s input places on the circuit under test.
• Most digital multimeters have high input impedance, which means a light load.
• Older analog meters and solenoid testers have low input impedance and can change a sensitive circuit.
• A low-impedance mode can help with ghost voltage, but it has limits.

Input impedance in plain terms

Input impedance is the resistance-like opposition the meter presents at its probe terminals. The Fluke article says most digital multimeters sold for industrial, electrical and electronic work have “high impedance input circuits greater than 1 megohm.” At that level, the meter takes very little current from the circuit, so the reading is close to the voltage that was there before you connected it.

Burden is the practical side of the same number. A lower input impedance draws more current from the circuit and loads it more. The article gives the contrast directly: older troubleshooting tools such as analog multimeters and solenoid testers “generally have low impedance input circuitry around 10 kilohms or less.”

Why burden can change a reading

When a meter loads a circuit, the reading can move from the true value. This matters most on sensitive electronics and control circuits, which can be disturbed by a load that a power circuit would ignore. The Fluke article notes that low-impedance tools “should only be used for testing power circuits or other circuits where the low impedance will not negatively impact or alter circuit performance.”

Ghost voltage and the low-impedance mode

A ghost voltage is a voltage that appears on a wire that is not actually connected to a live source. The Fluke article explains that it can occur when energized wiring sits close to non-energized wiring, such as in the same conduit or raceway. The energized wire couples a small voltage onto the idle wire through capacitance. The coupling capacitance forms a voltage divider with the meter’s input impedance. A high-impedance meter can display that voltage, so the reading can look like a live circuit when none is present.

The article describes the Fluke 114, 116 and 117 low-impedance setting, called Auto-V/LoZ, as a way to reduce this. It presents a low input impedance to the circuit, which lowers the chance of false readings from ghost voltage and helps when you are judging whether voltage is present. The article advises using Auto-V/LoZ when readings are suspect or when you are testing for the presence of voltage.

Where the low setting has limits

• Do not treat a low-impedance reading as a full test that a circuit is dead. The article warns against using these meters to confirm that a circuit is de-energized.
• The article says the low-impedance setting should not be used for troubleshooting high-energy three-phase distribution panels.
• For sensitive electronic loads, the article recommends the standard high-impedance VAC and VDC positions for most troubleshooting.

How to think about burden when you choose a meter

For most home, automotive and electronics work, a high-impedance input is the default. Check the meter’s specifications for its input impedance before you use it on a sensitive circuit. Where the listing or manual does not state a figure, the sources we opened do not give one either, and this post does not supply a number from memory.

Common mistakes

• Reading a faint voltage on an idle wire as proof that the wire is live. Check it with a method that does not depend on a single reading.
• Using an old low-impedance tool on a sensitive electronic circuit and then trusting the result.
• Assuming a low-impedance reading is always the correct one. Each mode answers a different question.

Safety first

Burden is a measurement issue, not a safety rating. Check the meter’s CAT rating and voltage rating before you connect it to any circuit. Work on mains circuits can kill, and panel or service work belongs to a licensed electrician. The Fluke article itself says low-impedance modes should not be used for troubleshooting high-energy three-phase distribution panels.

How we chose

This post answers one question: what meter burden means in practice and why input impedance matters. It uses the single Fluke article listed in Sources, which we opened on 2026-10-27. Because that article does not use the word burden, this post treats burden as the practical effect of input impedance and says so. It does not rank meters or add load figures from memory.

What we could not verify

The Fluke article does not cover the burden of current-measuring meters, such as the voltage drop across a shunt when measuring amps. It also does not state a load figure for any specific meter model. This post does not fill those gaps.

Frequently asked questions

Is burden the same as input impedance?

They are closely linked. Input impedance is the figure on the meter; burden is the practical load that figure places on the circuit. This post uses burden for that practical effect.

Why does a meter show voltage on a wire that is off?

That can be a ghost voltage. The Fluke article explains that a nearby energized wire can couple a voltage onto an idle wire, and a high-impedance meter can display it.

Should I use the low-impedance setting for everything?

No. The article recommends the standard high-impedance VAC and VDC positions for most troubleshooting, especially on sensitive electronic loads.

Does burden matter for current measurement?

The Fluke article does not cover current-measuring burden, so this post does not make a claim about it.

Bottom line

Meter burden is the load a meter places on the circuit through its input impedance. Most digital multimeters use a high-impedance input that loads the circuit very little. Use a low-impedance setting only when the reading is suspect, and never as the only check that a circuit is de-energized.

Related guides

• Best non-contact voltage testers, for a quick check before you touch wires.
• Best multimeters for AC voltage, for meters used on mains-level AC work.

Sources

• Fluke, “Dual Impedance Digital Multimeters,” https://www.fluke.com/en-us/learn/blog/digital-multimeters/dual-impedance-digital-multimeters (opened 2026-10-27)