ITTSB.EU Blog Forum
Electrical Test and Measurement instruments => Bench-top multimeter => Topic started by: Kiriakos GR on October 30, 2026, 06:55:00 PM
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Keithley advertised their DMM6500, as this be a milliohm sniper
I have plenty of experiences about using my FLUKE 8846A, especially at 4W resistance mode.
By using Kelvin clips and or genuine TL2X4W-PTII test lead, and I did succeed getting the most possible performance of it 10 Ohms range.
FLUKE this succeeds holding 6½ digits mode by the use of 10 NPLC and or 100 NPLC at resistance mode.
In contrast ...
Keithley DMM6500 this holding 6½ digits mode by the use of 1 NPLC and or 5 NPLC at resistance mode.
Just by reading Keithley documentation you starting to think that DMM6500 this is a modern king in accuracy and measuring stability.
BUT IT IS NOT .. :P
An Tektronix application engineer he presented video footage, with DMM6500 this be at 4W mode with default 1 NPLC.
The outcome this is three last digits these dancing around, human eyes they are unable read this measurement.
Keithley were forced to add a digital FILTER this creates a simulation of 10 NPLC.
Neither this gizmo succeed to make the measurement stable enough, and the test engineer applied and another second FILTER this be another software calculations gizmo, so to force further more averaging.
Keithley this is responsible of releasing poor design at DMM6500 and DMM7510 7½.
Both share 1 NPLC and or 5 NPLC at resistance mode.
Both have the software FILTER as 10 NPLC simulation.
At both you are obligated to use software scripts so to further stabilize measured reading.
https://youtu.be/sLeQrHlU7MI?t=162 (https://youtu.be/sLeQrHlU7MI?t=162)
Now I do finally understand, of why no one showoff footage of DMM7510 this measuring resistance of few milliohm. :P
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Greek feedback,
a) 2W mode unstable readings.
b) Auto Range issues in case of measuring inductive loads.
https://www.youtube.com/watch?v=ljZKrHYjTvc (https://www.youtube.com/watch?v=ljZKrHYjTvc)