Oh man, just my luck. And, it was $155. Thanks for your comment...If there was a way to purchase a known good KA200, I would do that, as I'm kind of obsessed with getting this right.
So, at $155 you *probably* got a good scale. Weirdly, fakes/rejects are almost never sold at "good brand" price points.
The marketplace in China is "weird" by our standards, especially for these niche industrial products, but for some reason distributors' markups are generally in the same ball park. I.e. you won't often see products marked up by 50%-100%. 10% is much more common. I.e. people selling DRO scales will try to set the price as low as they can to move the inventory fast.
As far as where to buy a "known good" scale, it's a tricky question. In my experience with DRO scales from China, they fall into three categories:
1. Ditron/Aikron - both are OEMs (for some value of OEM), and try to play the long game. The quality is good and support is better than average by Chinese standards. Their glass scales are [usually] spot on; magnetic scales are meh, but at least consistently "meh". Ditron has an official store on eBay and Amazon; Airkon has a direct-to-consumer we store. Ditron has a well equipped QA lab where they can check the scales on an interferometer stand (they sent me a video at one point, and were able to produce reports for their magnetic scales when asked). Don't know about Aikron, but I would bet some money they do as well.
2. White label scales (Vevor, Sino, ToAuto, etc.) - usually made by Ditron, but the level of QA varies depending on the price. These are almost always fine, but from time to time you might run into lemons.
3. Fakes (can be any "brand", but Sino is VERY popular, since it is a well known trademark in China and is no longer protected). There are two categories for these:
a. Quality rejects/dumpster finds from the "big" OEMs - you get crap
b. Scales build in small shops from parts bought from the larger OEMs - what you get depends on how lucky you are, since these are build basically in someone's garage, and the "company" can't afford test equipment to QA the end result. I have seen some that are complete crap, and some that were very well made.
In other words, going by the brand is useless. The moment a brand name becomes well known, the market is flooded with fakes, and then fakes of fakes. In my experience, people had decent luck with Ditron's official store on Amazon/eBay, Aikron, or Vevor (from their store).
Before throwing money at a new scales, I'd re-check your setup. If you have a consistent linear error (regardless of the resolution), the scales is good. If you get discrepancies between different travel intervals, but the numbers are stable, you have a bad encoder strip (bad etching), if you get inconsistent results over the same travel intervals, either the reader is sloppy or not adjusted correctly, or the DRO is skipping encoder pulses.
Regards
Yuriy
