Agilent U1252B Teardown/Review - Page 1
Forum section: electronics / general

author: gamozo
author_rank: Regular Contributor
timestamp: September 15, 2011, 01:36:17 pm
content: I finally got the Agilent U1252B. And I followed the standard procedure here of 'Don't turn it on, take it apart'.If you want more info, or something covered more in depth, feel free to ask. This is my first time doing a teardown and a review, so I know I missed stuff. Man, I need more enthusiasm.

author: shadowless
author_rank: Regular Contributor
timestamp: September 15, 2011, 05:47:59 pm
content: Great review.Quick question. Blown the 11a fuse in the u1252b, can i use fluke fuse in place of the SIBA fuses.Fluke fuses seems to be cheaper.

author: gamozo
author_rank: Regular Contributor
timestamp: September 15, 2011, 05:59:12 pm
content: I'm not quite sure on that. You may have to resort to directly contacting Agilent (although they may be biased just to get your money). Unless you can find the exact fuse specs somewhere online. I'm assuming there would be no issue, as they both are 11A HRC fuses, but maybe there are tiny things that could change compatibility. (Perhaps the size of the fuse in the first place, I wonder if it would even fit)

author: shadowless
author_rank: Regular Contributor
timestamp: September 15, 2011, 06:10:52 pm
content: Seems to be the same size base on the same amp rating. Everyone sells fluke fuses and they seems cheaper. Probably get the fluke ones.

author: Unknown
author_rank: Unknown
timestamp: September 15, 2011, 06:23:33 pm
content: Agilent uses fuses with a higher interrupt rating in some meters. I wouldn't use fuses with worse specs, all safety tests were performed with these specs in mind.

author: Fox
author_rank: Regular Contributor
timestamp: September 15, 2011, 07:00:13 pm
content: Good Review gamozoI like the case of Agilent Multimeters too, i have a U1241B and it has basically the same case as yours.@shadowlessi think you can use fuses from SIBA, they have dedicated fuses for usage in a Multimeter see the attached Pdf.Fluke uses fuses from Bussmann DMM-B Series if you looken for an other supplier than Fluke directly.The sizees of the fuses are standardised 10x38mm for the 11A and 10x35mm for the 440mA one.

author: Unknown
author_rank: Unknown
timestamp: September 15, 2011, 07:10:43 pm
content: The Agilent U1252B manual states that the fuses have an interrupt current of at least 30kA. Fluke fuses were 20kA last time I checked. Can't find the spec for Siba. My assumption is that since Agilent uses better fuses, they probably changed some other parameters so the expected fault current is higher. Why else would they go for more expensive fuses if the inputs are rated for the same CAT IV 600V / CAT III 1000V?

author: Fox
author_rank: Regular Contributor
timestamp: September 15, 2011, 07:21:40 pm
content: You can find the specs on the SIBA Site, thou they are not that easy to find. Search for the URZ Type Fuses.I attached the only specs for the 10x38mm Fuse, cause the Pdf for all of the URZ TYpe Fuse is just too big for the forum limits.

author: Unknown
author_rank: Unknown
timestamp: September 15, 2011, 07:38:36 pm
content: Thanks for the datasheet, a cursory search on the Siba website only yielded product catalogs. The specs you posted appear to match the Agilent specs, so I agree that the fuse should be fine. Funny how the 11A version is missing from many listings, though. You would expect it to be more popular than the 12A version.

author: saturation
author_rank: Super Contributor
timestamp: September 15, 2011, 08:20:52 pm
content: Thanks for the review! You can find other reviews on eevblog on the 1252a, is twin brother that's just a bit blue, just to compare notes.

author: Wartex
author_rank: Frequent Contributor
timestamp: September 15, 2011, 11:52:26 pm
content: Did you film this with a toilet plunger?

author: shadowless
author_rank: Regular Contributor
timestamp: September 16, 2011, 03:26:29 am
content: Yeah the SIBA fuses are 30ka and they are hard to find. Trying to ask for the agent in US. What is the difference between the 30ka and 20ka rating?I thought i will never blow them till yesterday. They are really fast blow, accidental touch of a battery terminals, one spark and they are gone.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: September 16, 2011, 04:27:24 am
content: If you take a CAT III 1000 V meter with the test leads in the amps jacks, you will have a seriesresistance of approximately 0.1 ohms (0.01 for the shunt, 0.04 for the test leads and 0.05 for thefuse and circuit board conductors) between the leads.Now when you accidentally place the leads across a 1,000 volt source, byOhms Law you will generate a current of 10,000 amps (E/R=I, 1,000/0.1 = 10,000).You want a fuse that will break that current and do it quickly.For the full story read this..http://assets.fluke.com/Appnotes/2041429_w.pdf

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: September 16, 2012, 06:47:10 pm
content: Quote from: gamozo on September 15, 2011, 01:36:17 pmHi,I would like to give you intense appreciation for this video teardown .Have USD 200 to spend and cannot think of anything better .any suggestions guys other then buying this

author: Baliszoft
author_rank: Frequent Contributor
timestamp: September 16, 2012, 07:16:18 pm
content: Usd200 wont buy you a 1252. I prefer it over on the 87V, if that helps.

author: nanofrog
author_rank: Super Contributor
timestamp: September 16, 2012, 08:16:22 pm
content: If you're after an Agilent,Baliszoftis correct. You'd actually need to double your budget for that meter in the US, and probably a bit more since you're in Europe. The U1242B would be much closer to your budget I suspect (~$216 - 226USD in the US).BTW, for anyone that is interested, the cheapest source for fuses I found (US) is directly from Agilent. Shipping was free, so I only paid ~$6USD for the 11A unit (pricing was less for the 440mA fuse).

author: Bored@Work
author_rank: Super Contributor
timestamp: September 16, 2012, 09:43:21 pm
content: Quote from: nanofrog on September 16, 2012, 08:16:22 pmSure, India is now in Europe ...

author: Unknown
author_rank: Unknown
timestamp: September 16, 2012, 11:02:16 pm
content: India and Europe are now two different countries? When did that happen?

author: nanofrog
author_rank: Super Contributor
timestamp: September 17, 2012, 01:52:54 am
content: Quote from: Bored@Work on September 16, 2012, 09:43:21 pmAccidentally saw Baliszoft's country flag rather than Amarbir's during my reply in regard to location. It was an honest mistake.

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: September 17, 2012, 04:19:29 am
content: Well,i have made a new thread for the same ->https://www.eevblog.com/forum/buysellwanted/wanted-digital-multimeter-for-usd-200-max-for-repairing-work/

author: Achilles
author_rank: Regular Contributor
timestamp: September 21, 2012, 12:17:02 pm
content: About the Fuse question again:Try to check out on the Agilent site or write your service center. I got my spare fuses there and they were much cheaper than in the online shops.The 11A Siba fuse was 7,54€ incl. VAT. A fluke 11A fuse is around 8,5€ incl. shipping.So it may be worth checking. You can check the prices only on the Agilent site if you go to the U1252B meter, on the right side you can click on a "spare parts" and see the fuses there. The prices there are excl. VAT and may change (mine were a bit cheaper).Well, they do have a minimum order of 35Euro here, so I bought a bunch of them and paid no shipping....just in case if you need spare fuses

author: LaurenceW
author_rank: Frequent Contributor
timestamp: September 22, 2012, 09:28:52 pm
content: Wow - do you REALLY have to strip the meter downthatfar, just to change a fuse? Hmmm

author: T4P
author_rank: Super Contributor
timestamp: September 23, 2012, 07:11:52 am
content: Quote from: LaurenceW on September 22, 2012, 09:28:52 pmIt's a good meter but that's just nuts, having to get to the other side of the board just to change the fuses

author: M. András
author_rank: Super Contributor
timestamp: September 23, 2012, 09:43:11 am
content: cos you are not supposed to pop the fuses

author: nanofrog
author_rank: Super Contributor
timestamp: September 23, 2012, 12:14:30 pm
content: Quote from: LaurenceW on September 22, 2012, 09:28:52 pmQuote from: T4P on September 23, 2012, 07:11:52 amNot the simplest fuse changes, but assuming the user isn't blowing one very often, I see it as an acceptable compromise for what the meter can do/offers in value, particularly for bench use. And it doesn't take that much time (could see it as a real PITA for field work though, particularly in regard to finding dropped/lost screws).

author: Wim_L
author_rank: Regular Contributor
timestamp: September 23, 2012, 01:32:52 pm
content: It's still a lot better than meters with an unfused 10A range!Just remember the fuse is a final safety net, not something you expect to replace all the time. With good measurement habits, blowing a meter fuse should be a rare event.

author: T4P
author_rank: Super Contributor
timestamp: September 23, 2012, 06:05:30 pm
content: Like a fluke fuse thread somewhere on the forums,You can have big caps suddenly discharging and*POOF*goes your fuse, at 5 pound a piece it ain't cheap

author: Wim_L
author_rank: Regular Contributor
timestamp: September 23, 2012, 08:11:14 pm
content: Mistakes happen, but shorting big charged caps with your multimeter on current mode probably shouldn't be standard practice.

author: M. András
author_rank: Super Contributor
timestamp: September 23, 2012, 08:31:10 pm
content: if you want to measure huge surge/peak currents then use a small resistor in series and measure the drop accross it or use a clamp meter. that multimeter fuse its not for shorting caps. and if its part of a circuit and by any means its not a spot welder then i dont want to be that circuit which has 10A+ surge currents

author: T4P
author_rank: Super Contributor
timestamp: September 23, 2012, 10:00:08 pm
content: https://www.eevblog.com/forum/product-reviews-photos-and-discussion/beware-the-price-of-some-fluke-fuse-replacement/'Nuff saidThings can be very unexpected

author: tooki
author_rank: Super Contributor
timestamp: August 20, 2017, 10:20:37 am
content: Quote from: LaurenceW on September 22, 2012, 09:28:52 pmNope, he took it apart wrong. You leave the 6 screws in place that hold together the two boards, and instead just remove the two screws that hold the display board to the housing. Then the board sandwich comes out as one unit, with the fuses easily exposed.