Watch this guy trying to destroy EEVBLOG 121GW meter  - Page 1
Forum section: electronics / general

author: unknownparticle
author_rank: Frequent Contributor
timestamp: December 16, 2019, 05:37:38 pm
content: Not just a guy, but Joe Smith, a frequent contributer here to say the least! He subjects many a meter to the same torture, all to determine how they perform, if they meet or exceed their claimed specs, value for money, reliability, durability etc, etc!

author: thm_w
author_rank: Super Contributor
timestamp: December 16, 2019, 10:20:46 pm
content: Has Joe commented on the effect of grease on contacts?Most meters I can find will plate the through hole for the selector switch. The Fluke 115 I have has grease on the selector switch as well.However, it does not have grease on the contacts themselves. I could see pros and cons to doing it.For sure the plastic case wear and selector switch wear would have been reduced with grease in those spots.

author: tooki
author_rank: Super Contributor
timestamp: December 16, 2019, 10:25:34 pm
content: Quote from: thm_w on December 16, 2019, 10:20:46 pmMaybe consider watching the video before commenting? He talks about grease (and the total lack of correlation between grease and longevity) quite a bit in the video.

author: tooki
author_rank: Super Contributor
timestamp: December 16, 2019, 10:28:49 pm
content: Quote from: slaghammer on December 16, 2019, 05:15:45 pmI think a good case could be made that he succeeded. The 121GW has some interesting, unique features, but alas the build quality seems to be disappointing. It certainly isn’t keeping up with other meters in the same price class.

author: thm_w
author_rank: Super Contributor
timestamp: December 16, 2019, 11:21:22 pm
content: Quote from: tooki on December 16, 2019, 10:25:34 pmI watched the whole 1hr video yesterday, didn't catch that part.Was he specifically referring to grease on the contacts or on the rotating plastic section? Very hard to believe it would make no difference for plastic on plastic wear.

author: tooki
author_rank: Super Contributor
timestamp: December 17, 2019, 06:26:48 am
content: I think he was talking about contacts primarily. I’m not so sure grease would have made a decisive difference, though. FR-4 is super abrasive, and its dust would be nearly as abrasive when suspended in grease, as a grinding fluid of sorts.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 17, 2019, 11:18:00 am
content: Quote from: thm_w on December 16, 2019, 11:21:22 pmI assume you are asking about packing the area with the detent spring and maybe where that stupid shim is rubbing. Dave has posted about the new revision of the meter not having a shim. The detent spring and lobes molded into the case are another story. We know they changed this design for some reason as Dave said they did. Maybe someone wanted it to be stiffer and didn't consider the wear it would cause. Who knows. Grease may help in that area but they would need to test it.Seeing it arc over between the two pads for the PTCs, maybe the grease would help. I was very surprised to see it arc over like this. Seems like a slot was needed but there is an inner trace running through that area. Just not well thought out, but would have expected people that design meters on a professional level would have known all of this upfront.In the end, it's really not anyone but UEi's and maybe to some degree Dave's job to come up with a working design. Maybe it meets their goals as is.It is safety rated after all.

author: thm_w
author_rank: Super Contributor
timestamp: December 17, 2019, 10:11:44 pm
content: Quote from: tooki on December 17, 2019, 06:26:48 amYeah grease on the shim, I don't see it doing so much unless its changed from FR4 on plastic to plastic on plastic. I suspect HDPE shim would have been similar price, maybe more upfront cost. But if it was a short term solution then doing that is not worth effort.Quote from: joeqsmith on December 17, 2019, 11:18:00 amYes the detent spring area.Good point about grease potentially helping with arcing as well, although not something you can rely on compared to the machined slot.I think it definitely is possible, and understandable, how it meets safety ratings but is not a comparably "robust" design.