|
I road tested the Keithley Bench Digital Multimeter DMM6500. I recently purchased a 2000-SCAN 10 channel scanner card. This 3rd post shows the 2-wire and 4-wire resistance measurement mode with the scanner card.
|
10 2-wire or 5 4-wire channels
The SCAN-2000 has 10 channels. They can all be assigned to different measurements. For this post, I'll check the resistance modes. You can use each channel individually to measure 10 resistors in a single scan. Or you can pair channels (1 with 6, 2 with 7, ...) and measure 5 resistors in 4-wire mode in a scan.
A combination is also possible. In the screen grab at the top of this post, channel 1 and 6 are paired for 4-wire mode, and channel 2 is in 2-wire mode. During a scan, the DMM6500 will switch to the correct mode for each configuration.
All measurements in this post include the extra resistance from the relay, test leads and contact resistance with a breadboard. But you 'll see that the 4-wire mode lessens those impacts.
2-wire
In the first test, I measured the resistance of a patch wire in a breadboard. On channel 1: 1.4Ω.
4-wire
Here, I measure that same patch wire in 4-wire mode. On channel 1 and 6 paired: 0.4Ω.
mixed
In this test, I have set:
- channel 1+ 6 in 4 wire, measuring a patch wire's resistance in 4-w
- channel 2: a 10K resistor in 2-w
- channel 3: a patch wire in 2-w:
