2006-09-07 02:35:51 · 2 answers · asked by true_friend 1 in Consumer Electronics ➔ Other - Electronics
What?
2006-09-07 06:03:27 · answer #1 · answered by stan l 7 · 0⤊ 1⤋
Low value precision resistors do have 4 terminals. Precision multimeters also have 4 terminals for measuring resistance. The function button on these meters is called "4 Wire Ohms."
Two terminals are for carrying the current and two terminals are used for measuring the voltage. On the resistor, the inner two terminals are the voltage terminals.
The problem is that current connection contacts may have a tiny amount of resistance themselves. Since the voltage measurement uses nearly zero current, if these contact points are made inside the current contacts (closer to the actual resistance material), then the measurement should be precise.
2006-09-07 13:54:00 · answer #2 · answered by Tom H 4 · 0⤊ 0⤋