why Keysight no longer provide MTBF? - Page 1
Forum section: electronics / testgear

author: Porama6400
author_rank: Regular Contributor
timestamp: May 28, 2022, 01:01:25 pm
content: earlier I was browsing datasheets for different 344XXA meters and it seems like MTBF was not mentioned for 34461A.I can’t figure out why they would want to hide MTBF for the newer product. did it go down? or is it not relevant anymore?MTBF is also not mentioned in the 1000-X series scope datasheet, even though it sounds like they have it.https://www.eevblog.com/forum/testgear/new-keysight-4-channel-scope-(1200-x-series)/msg2199081/#msg2199081p.s. It's such a shame the manufacturer no longer provides schematics. I would not care as much if I could open my gears up and fix them myself.34401A - MTBF provided (100kh)34411A - MTBF provided (100kh)34461A - MTBF not providedInfiniium S-Series - MTBF provided (110kh)6000 X-Series - MTBF provided (120kh)3000T X-Series - MTBF provided (250kh)3000A X-Series - MTBF not provided1000 X-Series - MTBF not provided

author: Kleinstein
author_rank: Super Contributor
timestamp: May 28, 2022, 04:04:01 pm
content: Unless you have a lot of data form long time use, the MTBF number are crude estimates and sometimes wishfull thinking.What is actual numbers will be is a thing time will tell, if the sold enough units to get a useful statistics at all.Getting a much higher failure rate than expected and possibly a component manufacturer withdrawing it's guess could be a reason to withdraw the number.

author: bdunham7
author_rank: Super Contributor
timestamp: May 28, 2022, 04:28:43 pm
content: I don't know why they would provide such a number in the first place unless some customer or another demanded it. MTBF is almost meaningless in this context and almost certainly doesn't mean what most casual readers would think it does. Annualized failure rate might mean something, but you absolutely will not have any accurate data until years after the product is released--anything before that or after any production changes is just a wild guess.

author: coppice
author_rank: Super Contributor
timestamp: May 28, 2022, 04:52:08 pm
content: 30 years ago HP and Tek were basically defence companies that also sold some stuff to the civilian market. Defence customers demand MTBF figures for everything they buy. Now, instrument sales for defence applications are not a big part of the total, so there is no longer a strong need to produce an MTBF figure for everything they sell.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 28, 2022, 06:25:12 pm
content: We also calculated them for automotive using the ground mobile criteria of 217. Eventually Prell was created. I have no idea what is done today.

author: nctnico
author_rank: Super Contributor
timestamp: May 28, 2022, 07:22:09 pm
content: Most modern hardware is extremely reliable. Realistically the MTBF is driven by components that wear like a fan and/or TFT backlight.

author: coppice
author_rank: Super Contributor
timestamp: May 28, 2022, 08:30:26 pm
content: Quote from: nctnico on May 28, 2022, 07:22:09 pmI have yet to replace a computer PSU because the fan failed. Its always the electronics.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 28, 2022, 08:59:20 pm
content: Running validation in those days, most of the problems were indeed mechanical. Solder fractures and pin fretting. We used a lot of potting compounds and conformal coatings and would see problems with these as well. I suspect that testing was a lot different than what you would do for a commercial product. We derated to where electronic component failures was rare. I would suggest we derated them that way because of the MTBF studies. Of course, then you put firmware in there....I would expect the medical and aviation fields also are sticklers for high reliability. I have a friend who does some work for part of the government and they are another group that demand high reliability. Certainly it's not just for military applications.