34470A_#2 = 10.000,178 V (+138 uV)
And immediately after that, I can see a drift in in trend chart.
Has anyone here experience the same with their 34470A?
Any ideas?
I'm beginning to think so yes. I've had mine for a year or two now, I picked it because of the autocal feature and the LTZ-1000, and bought it expressly for a few specific measurements:
1)1000 V with 1G input impedance- Well it doesn't and it's my fault, only up to 10V can have 1G Ohm input, above that, only 10M.
2) Measure 1G Ohm resistors with high precision. It should but it doesn't really. Up to 500M it seems fine, at 1G it takes forever to decide, basically .
For example, I've been working with 99M 0.1% resistors. What I need is 990M Ohms with precision and stability for a HV divider. The 34470A reads 99M swiftly and with stability, all are within tolerance./ Any two read 2X 99M, any 3 read 3X 99M and any 5 read 495M just as they should. Try to read all 10 resistors it gets muddy, same with a single 2W 1G 1% resistor
I trust the resistors, they show good on every instrument I own. I trust the series stack of resistors, they read fine on an ESI Guarded Wheatstone bridge and on an HP 4329A.
Some of the difficulty is in my inexperience with the modern high end, high tech instruments.
So far the ESI has proven the best instrument for me, it gives enough digits to be meaningful, and is rock steady, is fast and accurate. The 4329A is good and can read at 1000V which is what I need, but is analog, no resolution and rated rather poorly, although it does work very well.
I'm not disappointed yet but am confused and confounded, that something that should be easy is so hard to master.
George Dowell