Mine is an ebay one, and is still going good after a few years. Have a look in the google search option for "eBay refractometer" you will find many threads where I think the consensus will say all happy.
yep, awesome. just dont waste your time with getting one that reads SG scale on the side. IMO they are a PITA to read as the text for both is so small and i have 20/20 vision. multiply the figure by 4 and you're generally within 1 sg point. if you want accuracy, use a brix/plato to SG calculator.
I got one from China i think off of Ebay
Works perfect for when brewing E.G final runnings,Gravity of mash,first runnings,Gravity of boil
Only need to cool one drop of wort
Not so good with anything that has fermented
Mine has Brix and SG witch is is very easy to read (different to above)
Bought one from the same seller Fourstar linked. Works great, take a sample using the pipette from 80+deg and run under a tap for 10-15 secs and your good to go. Get a decent sized sample to begin with and you can discard the first few drips. Then take your sample at ~20deg.
I have one of the SG/Brix ones, and I would argue that BOTH scales are calibrated to sucrose solution rather than wort. I doubt that just because it is brix, that one side has some kind of correction factor scaled in.
My dioptre is loose, though it works. I am happy with that being a trade off for a cheaper unit.
I have checked against other instruments and mine is accurate, provided I have calibrated to water at the ambient temp (large temp swings make a difference).
My hydrometer does not agree with the refractometers in-bulit scale for gravity, so i trust the brix only on the refract.
Using the above website for fg readings, the corrected brix reading is always 3 to 4 points lower on the refract, so its not accurate/precise for fg, but using my refract the fg of my beers always seems to get to about 5 brix. If i mash higher they will finish a little higher.
I find the refract a useful tool to have. 30 bucks is a good investment if you are planning to measure the gravity of wort regularly.
After yet another broken hydrometer during a brew day last Saturday, I realised I spend more on broken hydrometers a year than it would cost to buy a refractometer.
So, I ordered one late Saturday, got the confirmation email on Monday, and it rocked up at my local Post Office yesterday.
I'm happy with it, and it seems easy enough to operate. I understand from some comments I've read elsewhere on this model that the SG chart is not necessarily too accurate, particularly at higher gravities, but I'm happy to let BeerSmith do a conversion from Brix for me.
Their blurb does say it is specifically created for brewing beer, and I like the fact it has automatic temperature compensation.