Wort Refractometer

[DCLavs]

Anyone have/tried one of these: http://www.ebay.co.uk/itm/RSG-100ATC-Black-Brix-Beer-Sugar-Wine-Wort-Tester-SG-0-32-Refractometer-Cool-/111452669482?pt=UK_Home_Garden_Food_SM&hash=item19f318c62a

Are they accurate?Seems a better way for testing gravity.

[CARA]

They're handy as fook, used one at a mates brew day and wanted one straight away! Great for constantly checking run off gravity when sparging

[imark]

I've one and it's one of the handiest yokes I've bought for brewday. You don't need to cool the sample as it's only a couple of drops so they pretty much cool on contact. Really useful for measuring gravity when lautering.
I've never had an issue with accuracy on mine after dozens of brews. Hold onto hydrometer for fermentation.

[mcgrath]

I have one. I love it. Makes brewday much easier. I brought mine to a brewery I volunteered in. Calibrated it off their one and it matched their readings after that.. I'd recommend them.

[DCLavs]

Downsides: No good for after fermentation has begun, it won't replace your hydrometer, dubious accuracy of Chinese made ones.

No good for testing FG then?

[armedcor]

There are calculations for using it to get FG but tbh it's easier to just use the hydrometer for the FG,

[rukkus]

The beersmith mobile app has a handy tool to do the fg adjustment for you, you need to know your pre ferment gravity for the conversion