Agilent/Keysight 3000X Series - User Calibration Fixture - Page 1
Forum section: electronics / testgear

author: Sparky
author_rank: Frequent Contributor
timestamp: June 04, 2017, 09:44:17 pm
content: Hello forum!It's time to perform a "User Calibration" on my MSO-X 3054A scope -- I've had it several years and not performed one yet!According to the Users Guide I need some items for the calibration procedure. I don't have the 50W RG58AU cables and BNC T connectors that is shown in the Users Guide (see pic attached), so I need to buy them, but before I go that route I wonder if anyone has tried Rigol's "DS6000 Calibration Kit" (see pic attached) for user calibration on any Keysight 2000X, 3000X or 4000X series scope?The Rigol hardware looks to achieve the same thing as required of the Keysight setup, and is very reasonably priced ($40 USD). I'm thinking it would work perfectly but check with people here, and perhaps someone has done this before? The Rigol kit has 1 "input" and 5 "outputs" -- would I need to use a 50ohm terminator on one output that is not required by Keysight's setup?Thanks folksSparky

author: TK
author_rank: Super Contributor
timestamp: June 04, 2017, 09:55:46 pm
content: In my opinion it is better to go with the cables and T connector model, as the configuration is more flexible and the components can be reused. The Rigol fixture serves one purpose only.

author: blacksheeplogic
author_rank: Frequent Contributor
timestamp: June 05, 2017, 12:44:00 am
content: Quote from: Sparky on June 04, 2017, 09:44:17 pmAside from the passage of time, what issues have you noticed? I would not overwrite my factory/lab cal without a need to do so.

author: Sparky
author_rank: Frequent Contributor
timestamp: June 05, 2017, 05:14:01 am
content: Quote from: TK on June 04, 2017, 09:55:46 pmCertainly true,TK. The BNC connectors and cables would be handy to have. I will price it out to see what it will costQuote from: blacksheeplogic on June 05, 2017, 12:44:00 amNo issues,blacksheep. Please correct me if I'm wrong, but I don't think the user calibration overwritesallthe parameters of a factory/lab calibration. For sure doing a user calibration will invalidate the NIST Calibration Certificate -- so be careful if that's important to you -- but overall it's not intended to replace factory/lab calibration. I think it's to allow users to self calibrate (and correct) basic parameters such as zero offsets and temperature correlated stuff.Quote from: blueskull on June 05, 2017, 12:53:08 amThat's super generous,blueskull! (What a scope! :O) Yes, I am in USA! I had a look at MSOX6004A user calibration procedure and it's much different -- apparently just one BNC cable, whereas for X3000 it's the setup shown in attachment with trigger out going to each of the inputs (2 or 4) simultaneously. Thanks for the offer, but looks like I need a few parts for this job.

author: Keysight DanielBogdanoff
author_rank: Unknown
timestamp: June 05, 2017, 06:37:27 am
content: I'm not a cal guy, but here's my thoughts.1. Having the BNC setup will likely come in handy again at some point, even as individual cables. Caution: if you try to calibrate with different length cables, it'll fail. BNC cables are generally pretty cheap, it's the 50 ohm and RF stuff that gets pricey in a hurry.2. It will overwrite factory & service center cals and invalidate those parameters3. Getting a certified cal gives you traceability back to known NIST values. A self cal will help converge uncertainty, but not necessarily to the actual correct value (higher precision, but unknown accuracy). Anywho, that's what the cal guys tell me. Doing a self-cal can be helpful, but if you're really needing certified traceable measurements get it to a certified cal lab.

author: blacksheeplogic
author_rank: Frequent Contributor
timestamp: June 05, 2017, 08:48:29 pm
content: Quote from: Keysight_DanielBogdanoff on June 05, 2017, 06:37:27 amThank you for confirming that, it is how I read the User Cal section but the wording could have been more specific.My 2c - rather than using time it would be better for the user cal section to define basic checks that should be run prior to performing a user cal.

author: [IDC]Dragon
author_rank: Contributor
timestamp: June 05, 2017, 09:10:53 pm
content: With network interface (telnet login) and a USB stick you can back up the original calibration before starting a user calibration.The files are located in the \secure\cal directory.There's also an existing log from such a user calibration, it seems the end of line procedure at Keysight runs that, too.

author: Sparky
author_rank: Frequent Contributor
timestamp: June 18, 2017, 02:13:06 am
content: Thanks, @Daniel, blacksheeplogic and Dragon.I went ahead with the individual cables -- it is a good idea to have those on hand.Thanks, Dragon, about the cal data on the scope -- I made a back-up of that right away!