Hi, I bought two magnetic bases and two 0-1" – 0.0005" resolution dial indicators many years ago from Chronos Tools, which were not that expensive, and none of them have any brand name, although the dial indicators were made in China. The dial indicators still work very smoothly, and this evening I gave one a simple check using a precision ground block that came off a second hand indicator that I bought. I didn't need the block on the indicator, as the shape on the other side wasn't much use for my needs, when using it with the indicator, but does make a good true spacer for other jobs.
Shown below is my dial indicator and magnetic base attached to my small surface table, with the indicator set to zero with the plunger touching the table.
The block was measured in several different places on each of the two sides, and came out at 25.08mm.
The block was then placed on the table under the indicator plunger, and a reading was taken at 0.9875". The block was rotated so to get a reading on all four edges, and the reading stayed the same, and I repeated the procedure three times and got the same reading each time.
So, 25.08mm = 0.9874" near as, and so my reading of 0.9875" looks pretty good to me for an unbranded dial indicator made in China.
Regards Nick.