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I was not aware of the existence of the spreadsheet until today since you mentioned it, I went in search of it, and yes it does in fact show that the 869 had not been subjected to same tests as many of the others had been (was there a particular reason for this by the way?)
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Perhaps if I could make a suggestion here as a consumer of your product, might it be an idea to include a reference to where the spreadsheet for further in depth information can be found added into your usual signing off on a video, maybe a as an on screen annotation at the end?
It's not really much of a product. I'm not making any money from it. The complete opposite actually.
I add the link to the FAQ and spreadsheet to the descriptions now. It's always been in the very first post of thread I started way back when that covers these tests. It's also linked in the About menu off my main page.
Yes, there was a reason the first BM859s was tested this way. It was the same reason that I skipped all of the levels on the UT139C and the Fluke 87V that people were so emotional about.
Old story compressing three years into a few paragraphs..
Early on I played around with some damaged meters I had ran to get a feel for what sort of levels would be required to damage a meter. I then bought the first set of $50 and under class meters and designed a generator to run them. Every time the meters would survive, I would have to redesign and construct the generator to increase the transient. By the time I was down to only two meters, the AMPROBE AM510 and the Fluke 101, the generator had been rebuilt several times. After the AMPROBE was damaged, I continued to push the Fluke 101 to see just how much it could handle. I made it to 12KV. There was a member on this site that had been following the thread and videos that had access to an actual IEC combo generator. They were very interested in seeing if the Fluke 101 would actually survive at these level on a commercial generator. After they disclosed their intent, I wanted to make sure the 101 was not on the edge. So I pushed the levels to 13KV with a 100us FWHH using the 2ohm source, knowing they were going to test at 12KV 50us FWHH. The 101 survived both of our independent tests.
Fast forward to the second set of meters donated by 5KY. You have no idea how much effort it was to run that first set of meters. There was no way I wanted to repeat that and now that I had some idea on what I needed to expose the meters to, I set out to design a programmable transient generator with the sole purpose to stress the meter's input stages to failure. I did not want to use any of the parts from the original generator in case I ever wanted to go back and repeat that high level test. I set the upper limit of this generator based on where the AMPROBE AM510 was damaged from the first set. Assuming any meter that survives to that level is going to be fairly robust, electrically.
The BM869s was part of that second set. I ran it along with all the other meters. In the end, there were only two meters alive. The Brymen, and the Fluke 107. I was in communications with Brymen throughout the tests. I made them aware it had survived and that I was thinking to expose it to the same levels that the Fluke 101 had been tested to. They were very interested in seeing this test ran. Something I continue to see with Brymen. They know the meters are on a level playing field with me and they will willing to show what they have. Anyway, they actually offer to replace/repair the meter if I damage it. So I run the test on both the 107 and BM869s. The 107 survived and the BM869s was damaged.
People wanted to know how close the BM869s was to the Flukes. I had already repeated testing on the UNI-T UT139C for this same reason and decided to go back and modify the original transient generator to give it some means to be programmed. After this, I started running meters at even higher levels. It became apparent that there were companies that knew how to make very robust meters and others that were left in the dust.
There was a lot of chat on this site from the Fluke fanboys about how the 87V would out live the BM879s. The general thought was, time will tell. I wanted to accelerate this so I started thinking about how to life cycle the selector switches. I spoke with Brymen about running a life cycle test on the BM869s. I showed them what I was doing and they were all in. They sent me, free of charge a new BM869s to run this test on. The meter held up very well to this test. Dare I say second only to the Fluke 17B+ I had tested. Yes, I will.
When it was all done, I decided to take that same meter which at that time had not been exposed to any transient tests and decided to repeat the testing at the higher levels to get a better idea how it would perform. Eventually I damaged the meter but again, I was able to repair it. The failure was the same as the original meter. just some leaking parts in the high speed clamp. So I hunted down what I thought would handle these stress levels and made another video where I modified the meter using them and proceeded to push the meter even further. None of that is documented in the spreadsheet but the video is still on-line.
I do continue to use/abuse both meters and they continue to be my all time favorite handheld meter and I have looked at a lot of meters. And that is the story of the BM869s.