What is a four-terminal sensing (4-wire) measurement?
1 Answer
A four-terminal sensing (4-wire) measurement is a technique used in electrical measurements to accurately determine the resistance, voltage, or current of a device or material with minimal interference from the connecting wires' resistance. It is commonly employed when dealing with low-resistance and high-precision measurements.
In a typical electrical measurement, the resistance of the connecting wires can have a significant impact on the accuracy of the result, especially when measuring low-resistance values. This is due to the fact that the resistance of the wires adds up to the measured resistance, leading to errors in the final measurement.
The four-terminal sensing method addresses this issue by using four separate connections to the device under test (DUT). Two of these terminals are used to pass a known current through the DUT, and the other two terminals are used to measure the voltage drop across the DUT.
The setup consists of the following four terminals:
Current Terminals (Source Terminals): These terminals are used to apply a known current to the DUT. The current is sourced through these terminals and passes through the DUT.
Voltage Terminals (Sense Terminals): These terminals are used to measure the voltage across the DUT. The voltage drop across the DUT is measured using these terminals.
The key advantage of this four-terminal sensing configuration is that the current-carrying terminals are separate from the voltage-sensing terminals, so the voltage measurement is not affected by the resistance of the current-carrying wires. The result is a more accurate measurement of the DUT's resistance, voltage, or current, as it eliminates the error caused by the resistance of the connecting wires.
Four-terminal sensing is commonly used in various applications, including measurements in electronics, materials testing, semiconductor characterization, and other fields where precise and low-resistance measurements are necessary.
In a typical electrical measurement, the resistance of the connecting wires can have a significant impact on the accuracy of the result, especially when measuring low-resistance values. This is due to the fact that the resistance of the wires adds up to the measured resistance, leading to errors in the final measurement.
The four-terminal sensing method addresses this issue by using four separate connections to the device under test (DUT). Two of these terminals are used to pass a known current through the DUT, and the other two terminals are used to measure the voltage drop across the DUT.
The setup consists of the following four terminals:
Current Terminals (Source Terminals): These terminals are used to apply a known current to the DUT. The current is sourced through these terminals and passes through the DUT.
Voltage Terminals (Sense Terminals): These terminals are used to measure the voltage across the DUT. The voltage drop across the DUT is measured using these terminals.
The key advantage of this four-terminal sensing configuration is that the current-carrying terminals are separate from the voltage-sensing terminals, so the voltage measurement is not affected by the resistance of the current-carrying wires. The result is a more accurate measurement of the DUT's resistance, voltage, or current, as it eliminates the error caused by the resistance of the connecting wires.
Four-terminal sensing is commonly used in various applications, including measurements in electronics, materials testing, semiconductor characterization, and other fields where precise and low-resistance measurements are necessary.