I wonder if someone out there has worked with these meters and has an opinion?
Based upon 1 year specs, they are virtually identical where they share the same ranges, see attached 8845 to 34401 spec comparison.pdf, this is denoted by the TAR of 1:1 Where the TAR is less than 1:1, the 8845A is more accurate, the 8845A has more capabilty than the 34401-lower and higher current measuring capabilty. Being an ex Fluke(r), I'm happy they are back in the bench DMM game.
Statistcally speaking, we have cal'd 2 8845's both in tolerance and 250 34401's 238 in tolerance-see attached 34401AIntervalAnalysis.pdf
Pretty well agree w/WestCoast. I had the option of selecting 34401A or 8846A for our use and in talking to the techs that deal with them the 8846A input connectors were not as robust, guess whatever it is they are attached to or the attachment point is a bit weak.
I went with 33401A because I already had 5 or 6 and leaned towards standardization/ruggedness rather than the enhanced functionality.
I have found that despite working in a laboratory environment things still get roughed up more than you'd think.
Yeah, my old lab just got them fielded to them, the 8846As that is.
Great meter, lousy input connectors. Very brittle and I noticed they were bending and taking a lot of wear after only a few uses using brand new Pomona cables. Either Fluke meant them for use with only special Fluke cables (never saw any) or someone short changed Fluke on the parts or they just went el cheapo.
I personally, as much as I HATE it, stick with the tried and true Agilent stuff. Face it, they have been consistently making the products we need without the long gaps in production. Not to mention Agilent hasn't closed and moved one of their largest production facilities, they have been making stuff overseas for a while.
I do wish there was quality, affordable, Made in the USA test equipment, but unfortunately that'll probably never happen again.....
Oh, and I have never worked with the 34401 save for a few automated cals on them. We use the 34420As a LOT though.
Just in case anyone is interested, attached is a reliability report for 115 samples for a Keithley 2000 (1 year specifications) made here in the good 'Ol U S of A in Cleveland, OH. I did get a chance to visit their production facility a couple years ago and it was pretty cool and they have some really nice people working there. With the exception of the 100 k and 1 M Ohm test points (which still calculated to just under 90%), these instruments have shown good reliability. By the way the IA method is NCSL A3.
What software did you use to produce the interval analysis?
MudCats
FWIW Tektronix has some DMMs too, DMM4000 series. Look an awful lot like the Fluke product but I did not compare specs.
Quote from: Bryan on 10-12-2009 -- 17:44:44
FWIW Tektronix has some DMMs too, DMM4000 series. Look an awful lot like the Fluke product but I did not compare specs.
Could be because Danaher owns them both...
i did not know that, had never heard of them but googled it and you are correct.
Don't forget Agilent has a newer 34410A and 34411A..
If you want to compair them by generation
HP 34401A to Fluke 8840A (or AF)
HP 3441xA to Fluke 8845\46A
Good point Mike, in case anyone is interested in the accuracies between the 34410 and 8846 (1 year specs) see attached. If the TAR is >1.0 the 8846 is more accurate, if the
TAR is <1.0 the 34410 is more accurate. Obviously if the TAR is 1.0, then they are equal accuracy (or within 10 ppm of each other)
I was very impressed with the 34410A.
About 5 years back, we wrote a Calibration procedure for the 34410A\11A for Agilent. Agilent Customer support wanted to have on program, per the manufactures manual available for self maintainers.
When we were final testing the procedure, they had a 34410A, that was their proto-type. It had not been calibrated in 5 years, and when we tested it, it was right on the money.
It is not a 3458A, but it is an impressive little meter.
Well while we are debating meters a feature of the 34401A that is useful to me is the language can be set to HP 3478A, Fluke 8840A or SCPI. I use that feature ocasionally with older test programs. It's probably not 100% but I haven't found the flaw yet.
Do I get a commision for this?
And I have a 34420 that I use exclusively to measure temperature. The revision to the firmware which allows you to enter ITS-90 coefficients for SPRTs so they'll readout directly in temperature is really handy.
I've calibrated more 34401A's than I care to remember. I am guessing any of us who work in at least moderate volume general type labs rarely have a week on the incoming shelves that doesn't include at least one.
I like the very intuitive software cal routine on the 34401A, and the main OOT (Out-Of-Tolerance) I see on them is users who constantly use DC mA, and the shunts age. So I think they're still good solid meters.
We've got a couple of 8845A's that I haven't used much yet. As the lead metrologist, I don't do many of the every day cals any more. So I actually haven't spent much time using the 8845A yet. Don't they have a higher current range?
Regarding the 34420A, that is a great little meter. I believe some of the low resistance readings, it is spec'd better than a 3458A. And the same is true of low DCV (as it has that sweet 1 mV range). The main problem I've seen on them is a little flakiness in four wire resistances. Where I used to work our customer had some 34420A's with modified Burns B12001 probes (with the 34420A connectors). I used to do comparison cals on them against our Hart super probe (5699 I think), and enter the coefficients. I used to post cal correlations and got typically to within +/-0.002 or so correlation. Very good solid, stable meters.
I haven't tried out a 34410A. Although a little off topic, I love my 8508A's with rear input option.