Rigol DS1054Z calibration & adjustment - Page 1
Forum section: electronics / testgear

author: bitseeker
author_rank: Super Contributor
timestamp: May 22, 2016, 07:39:40 am
content: Out of curiosity, I was doing some searching here and on the web at large regarding calibration/adjustment for the 1054 (i.e., not referring to the built-in auto-cal), but found nothing fruitful thus far. It may or may not need an adjustment in the coming years, but if it does, then what?I don't think the usual calibration services handle these. I suppose Rigol would be happy to take your money. However, I only need it to be accurate relative to other instruments in my lab (i.e., adjusted to an in-house reference), not NIST. In other words, DIY calibration.Given its price class, it might be considered relatively disposable.Is that its ultimate fate? I suppose it could go on living for qualitative see-if-something's-there use, should it actually drift so far from where it should be.Mine is still under warranty, so I haven't taken it apart, yet. Just thinking aloud.

author: tautech
author_rank: Super Contributor
timestamp: May 22, 2016, 07:46:06 am
content: It should be outlined in a Service manual, have you tried to find one?TDS Teks in the past had a button press sequence to enter service mode in which each of the adjustable parameters could then be checked and adjusted against a known reference.These days many DSO's a calibrated against the like of a Fluke scope calibrator, the model should be stated on your scopes Cal cert.

author: bitseeker
author_rank: Super Contributor
timestamp: May 22, 2016, 07:57:21 am
content: Yes, I've tried to find a service manual. Perhaps others have better Google-Fu than I. However, I vaguely recall a post or two about the lack of much technical information about these scopes. Hence, my ponderings.

author: Fungus
author_rank: Super Contributor
timestamp: May 22, 2016, 08:31:03 am
content: Quote from: bitseeker on May 22, 2016, 07:39:40 amIs it out of spec now? If it isn't then there's no reason to think it ever will be.Quote from: bitseeker on May 22, 2016, 07:39:40 amThat's actually its main purpose.Oscilloscopes aren't multimeters. You shouldn't expect highly accurate voltage measurements from them.Most DSOs use 8-bit ADCs attached to circuitry that's designed to respond to high frequencies. This means you have about 1% accuracy underidealconditions (and that'sonlywhen your vertical gain is set so that the signal occupies the whole screen).The specs for the DS1054Z are:DC Gain Accuracy: <10 mV: ±4% full scale, ?10 mV: ±3% full scaleDC Offset Accuracy: ±0.1 div ±2 mV ±1% offset value1% offset error + 3% gain error could add up to 4%. Add in the ADC error, improper vertical scale setting, some RF noise from the lights, imperfect probing, etc. and you can easily have 5-10% error in the on-screen numbers.Bottom line: Oscilloscopesaren'tmultimeters.(Yes, I'm sure there's some old green-screen "Tek" that's sub-1% accurate, but... )Quote from: bitseeker on May 22, 2016, 07:57:21 amI doubt they have anything more than their self-calibration function.

author: EI6JA
author_rank: Newbie
timestamp: May 22, 2016, 05:02:56 pm
content: The Performance Verification Guide is available athttp://beyondmeasure.rigoltech.com/acton/attachment/1579/f-0564/1/-/-/-/-/DS1000Z%20MSO1000Z%20Performance%20Verification%20Guide.pdfIt does not cover adjustment but should let you know if your oscilloscope is within specification.

author: uncle_bob
author_rank: Unknown
timestamp: May 23, 2016, 12:14:19 am
content: HiI would not be surprised if there isn't much calibration on this scope. All of the timebase stuff is run off of a fixed crystal oscillator. If it's off ... replace it. All of the bandwidth stuff appears to be select at test parts. About all that leaves are the gains. At the precision of the scope, that may all be dependent on fixed ratio resistors. Again, if they are broke ... replace them.Bob

author: bitseeker
author_rank: Super Contributor
timestamp: May 23, 2016, 01:53:15 am
content: Thanks for the insights. My prior scope was a CRO, so it was mostly a case of curiosity as to what the long run is like for a DSO. If it does end up just being component replacements, no big deal. Alas, with the way electronics are these days, it'll probably be replaced by some bigger fancier scope before it goes out of whack.

author: tautech
author_rank: Super Contributor
timestamp: May 23, 2016, 02:03:30 am
content: Quote from: Fungus on May 22, 2016, 08:31:03 amQuote from: bitseeker on May 23, 2016, 01:53:15 amTo give you some idea of what's involved with a modern DSO check the SM for a basic Siglent DSO:http://www.siglentamerica.com/Uploadfile/file/20140925/SDS1000CML_ServiceManual_en.pdfPages 26 & 27 list the gear needed and describe the steps involved in the process.

author: bitseeker
author_rank: Super Contributor
timestamp: May 23, 2016, 04:33:26 am
content: Thanks, tautech. Not much to it. Just click "test".Oh, wait. I need a Fluke 9500B.Even though there isn't a similar Rigol document handy, I'm sure it's something similarly automated.

author: tautech
author_rank: Super Contributor
timestamp: May 23, 2016, 05:05:48 am
content: Quote from: bitseeker on May 23, 2016, 04:33:26 amThere will be but maybe not in the public domain.....yet.One wouldexpectthe Self Cal process toflaga failure when it doesn't meet spec and warn the user that a full Calibration or repair is needed.Depending on how involved and smart the Self Cal is it might even point to the failure, something like the warning in this post:https://www.eevblog.com/forum/testgear/oh-no!-i'm-never-buying-any-agilent-keysight-equiment-ever-again!/msg945126/#msg945126Until you see warning flags......continue normal transmission.Link fixed

author: bitseeker
author_rank: Super Contributor
timestamp: May 23, 2016, 06:05:30 am
content: Roger! Normal transmission transmitting...normally.