Products > Test Equipment
Keysight's new 34465A (6.5 digit) and 34470A (7.5 digit) bench multimeters
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Faith:

--- Quote from: floobydust on July 23, 2017, 06:11:20 am ---Try put the cap/resistor under test right in the input jacks, compared to at the end of the test leads.

I find the LSD moving around so much on 34461's on resistance and worse on capacitance, I had to laugh at all those supposed extra digits.
--- End quote ---

Thanks for your quick reply!

I'll give that a try later once I've gathered all the data for my current test run!


--- Quote from: floobydust on July 23, 2017, 06:11:20 am --- You new lab might have more noise/different grounding and layout.
--- End quote ---

Yep that came to mind >,<"... though every other measurement (volts & amps) are pretty quiet.

I'll also point out that I do not by any means require super-accurate measurements (hobbyist and all), but my 34465A is my best DMM so I treat it as my reference point for every other meter and hence I like to make sure it works properly.

So just want to make sure that there isn't any other underlying problem with the meter that's causing this or potentially any other issue.
HighVoltage:
Do a 4 wire resistance measurement of a 1 Ohm resistor and compare the noise level.

Any kind of RF transmitter, phone, wireless router, neighbors router and so on can have a significant influence on the digits, especially when you measure a 100k resistor with 2 wires. I don't think there is something wrong with your 34465A.

floobydust:
As far as I investigated, something for others to keep an eye on, these meters use a mains SMPS and associated Y-capacitors.
So they generate their own common-mode noise- that seemed to be what I was seeing.

I would be curious if it's the lab/setup noise or the meter's have a sensitivity to RF.
TheSteve:

--- Quote from: floobydust on July 24, 2017, 07:07:00 pm ---As far as I investigated, something for others to keep an eye on, these meters use a mains SMPS and associated Y-capacitors.
So they generate their own common-mode noise- that seemed to be what I was seeing.

I would be curious if it's the lab/setup noise or the meter's have a sensitivity to RF.

--- End quote ---

What leads you to believe these meters use a SMPS?
HighVoltage:

--- Quote from: floobydust on July 24, 2017, 07:07:00 pm ---As far as I investigated, something for others to keep an eye on, these meters use a mains SMPS and associated Y-capacitors.
So they generate their own common-mode noise- that seemed to be what I was seeing.

--- End quote ---

These meters and previous models of Agilent meters have all a linear power supply and no SMPS !
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