Cool find. But at $60 too much to spend if it doesn't work pretty well.
Also resolution 0.5 doesn't sound very good. The optical ones are readable to 0.1 right?
Here's the one Santa bought himself in October, when the one on the right failed its "bench test" (falling off a 1 meter bench). Can't remember what I, er that is, HE paid for it, but it was under $100.
I'm pleased with the performance, it's easy to use, and actually uses LESS of a sample than the analog refractometer. The accuracy is +/- 0.2% Brix but the resolution is +/- 0.1% Brix. With the optical refractometer resolution is in 0.2% for every degree °Brix, so accuracy would inherently be subject to at least a 0.2% error depending on your eyesight and ability to interpolate. In that regard I feel that the digital is therefore more 'accurate', or at least more consistent.
Range is 0 to 85% Brix, nearly 3 times greater than analog, measurements take 1.5 seconds, and ATC compensates between 50°F - 104°F, with a digital readout of the sample temperature below the Brix readout.
It came with a padded hard side case, supply of pipettes and a small bottle of steam-distilled water for cleaning and calibration. Calibration between samples can be done in less than two seconds, but is unnecessary and will stay in non-volatile memory until you recalibrate.
When I first started using the digital, I ran parallel readings off the optical refractometer as well as a set of narrow range hydrometers. The readings were all either identical or within an insignificant differential, and the digital was always in agreement with at least one of the other devices (never the "odd man out").
So I'm happy with the digital, but then I was happy with the optical as well, right up to the moment I dropped it on the concrete floor. It still works if you jiggle it just right, but obviously something (lens) got knocked out of whack and can no longer be trusted. A replacement optical would have been about the same price for the same quality, but would not have been as easy to use as the digital.
Plus, you know, Bling.