ruxton.stanislaw
Senior Member
- Location
- Arkansas
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- Laboratory Engineer
Multimeter burden voltage refers to the voltage drop caused by the current flowing through the multimeter itself when you're measuring current. It's important to understand burden voltage because it can affect the accuracy of your current readings, especially when working with low voltage circuits.
Here's a breakdown of multimeter burden voltage:
How it Happens:
Here's a breakdown of multimeter burden voltage:
How it Happens:
- Traditional multimeters use a shunt resistor to measure current. This resistor allows a portion of the current to flow through it, and the voltage drop across the resistor is measured by the multimeter.
- The resistance of the shunt resistor creates a small voltage drop. This voltage drop is the burden voltage.
- Multimeter Range: The burden voltage typically varies depending on the current range you've selected on your multimeter. Lower current ranges usually have higher burden voltages because they use higher resistance shunt resistors.
- Shunt Resistor Value: The specific value of the shunt resistor used in the multimeter directly affects the burden voltage. Higher resistance shunt resistors will result in higher burden voltage.
- Inaccurate Readings: In low voltage circuits, the burden voltage can be significant compared to the actual voltage being measured. This can lead to inaccurate current readings. For example, if you're measuring a small current in a low voltage circuit, the burden voltage from the multimeter might be a high percentage of the actual voltage, causing the multimeter to overestimate the current.
- Use the Appropriate Range: Always choose the highest current range on your multimeter that will still provide a readable measurement. This minimizes the shunt resistor value and reduces the burden voltage.
- Consider Multimeter Specifications: Some multimeters are designed with lower burden voltage for better accuracy in low current measurements. Look for this specification when purchasing a multimeter.
- Four-Wire Method (Advanced): For high-precision measurements in low voltage circuits, a four-wire method can be used. This eliminates the voltage drop caused by the test leads, improving accuracy.
- Multimeter manuals typically specify the burden voltage for each current range. This information is crucial for understanding the limitations of your meter and interpreting your measurements.
- If you're working with very low voltage circuits and require high precision, consider using specialized current measurement tools designed to minimize burden voltage.
