| Products > Test Equipment |
| Keysight's new 34465A (6.5 digit) and 34470A (7.5 digit) bench multimeters |
| << < (103/145) > >> |
| LaurentR:
Note that I don't know how good the internal temp sensor is. I have a 34461A and a 34465A and they are about 2C different... I asked Keysight a while ago about this and they said: "The temperature shown in the 34461A calibration window is the internal temperature of the instrument. The temperature sensor is located on the PC board. This temperature/sensor is not calibrated. Changes in the internal temperature should correlate to changes in the ambient temperature." |
| kj7e:
--- Quote from: Alex Nikitin on October 21, 2016, 06:02:01 pm ---It looks like our 34465A is failing the noise spec on 10K. I'll talk to Keysight on Monday. It would be nice if somebody with the 34465A would repeat this resistance test (10K, 100NPLC, 10 sec logging interval). Cheers Alex --- End quote --- I know your meter was replaced already, but I was curious to try this myself. 10K, 10NPLC over 12 hours with temp plot overlay. VPG, Z201 in a shielded enclosure; https://www.eevblog.com/forum/metrology/resistance-standard-shielding-how-important-is-it/ So if I'm reading this correctly, this shows 1.4ppm Std dev over 12 hours, much of that is tempco; |
| kj7e:
--- Quote from: Alex Nikitin on October 31, 2016, 12:03:33 pm ---An update. I've received the replacement 34465A last week and it was on continuously for about 100 hours so far. I've run a log over the weekend measuring the LTZ1000 and the meter drifted about 4ppm down, however ACAL this morning returned the results to within 1ppm of measured by HP3458A previously. The resistance ranges are now nice and stable, the attached graph shows 1 hour log for two 34465A and HP3458A - all for NPLC 100 measuring my 10K LTC450C reference resistor (taken at different times, obviously, but with a fairly constant temperature in the lab for each run). Keysight UK was very helpful in resolving this problem. I aslo should get the 3458A Opt 002 back from them later this week so I will have a freshly calibrated reference. Cheers Alex --- End quote --- My attempt to duplicate your 1 hour, 100NPLC, 10K 4W, 2ppm full vertical scale with lines at 0.5ppm; Edit, typo in the chart title, should be 34465a. |
| Faith:
Hey everyone. So I've finally managed to get my new lab set up after finally securing, designing and renovating the interior of my home. I did however have everything in storage for several months during my housing woes to make moving around easier. So anyhow now that everything's back up and running I did a quick check on all of my equipment today and I realised that my 34465A is a lot noisier than I remember on the ohms range (particularly 10K-100K). When measuring a 100K resistor on the 100K ohms range at 10PLC the reading jumps after each update with a variance of up to 5 ohms. At 100PLC it's a little less noisy (though I suspect due to averaging?) but I still see a variance of several hundred milliohms following each update. I don't have a proper sealed resistance standard but I do have a pile of Vishay PTF56 resistors lying around which I used for testing (during the afternoon, no lights, and everything else powered down). Is this normal? I don't recall this behaviour when I last used this instrument. It's been running for an hour now so I've just cleared its statistics and will let it gather more data for the next couple of hours. |
| floobydust:
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. I traced it down to some sensitivity to hum or common-mode noise on the 34461's. Even on a "quiet" bench with no other equipment. You new lab might have more noise/different grounding and layout. |
| Navigation |
| Message Index |
| Next page |
| Previous page |