Found this while looking for a ph meter.
http://www.milwaukeetesters.com/MA871.html
Anyone using it? How you like it?
http://www.milwaukeetesters.com/MA871.html
Anyone using it? How you like it?
Digital refractometer
- Thread starter nilo
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BayerischBier
Well-Known Member
How much is it?
Cannot find any pricing for their products.
Cannot find any pricing for their products.
karmabrew
Well-Known Member
I just did a Bing shopping search and they can cost anywhere from a few hundred to thousands of dollars.
That's one of the advantages of the digital design. The light never actually enters the sample. It is reflected off it. But even in the transmission (Abbe) design the film of beer/wort is very thin. A beer of 127 SRM exhibits absorption (at 430 nm - blue) of 10 A in 1 cm. In a 1 mm path, it is 1 A, in a 0.5 nm path, 0.5 A etc. But refractometers measure at 589 nm (yellow sodium line) where the absorptions will be about 1/5th of the 430 nm values.
Ok, translating it, it is accurate regardless the lovibond?
It should accurately measure refractive index. Whether the refractive index of a highly colored (or any other, for that matter) beer is close to the refractive index of a sucrose solution (what the instrument is calibrated for) of equal sugar content is another question. In general, it seems to work. Sometimes it can be off by 1 Bx or more. That's why I don't think refractometers are good for much beyond monitoring runoff during sparging.
Bigscience
Well-Known Member
So do you have one or have used one before?
I like the idea of using one because it gives a number and I don't have to try to stare at a little scale. I'll chart my fermentations to see see how they are coming along but when they're done I'll verify by hydrometer. After compensating for temperature and the individual hydrometer's calibration, the results are right on.
How would I know they can be off by a Bx or more if I didn't have one?
I like the idea too. That's why I got a couple and started checking them out against hydrometer and density meter. I didn't find the agreement that good. Unfortunately I'm overseas at the moment and can't look at my notes or I'd be more specific.
Post fermentation it's necessary to correct for alcohol content so I assume that you are doing that as well. There are several spreadsheets about that will do this for you (e.g the one from MoreBeer which corrects for alcohol and temperature based on original refractometer reading).
One thing I do remember in particular is that the refractive index of beer and the refractive index of sucrose solutions do not change with temperature at the same rate so refractometer ATC, based on sucrose, isn't going to work very well.
Refractometers are, of course, great for monitoring progress of sparging or fermentation. Beyond that, I'm not too keen on them.
I have not used that one, but I own this one and am quite happy with it.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220443962351
Bigscience
Well-Known Member
You could have read an article, heard from a friend, seen it in a forum and so on. I was wanting to know if you owned one and used it on a regular basis and how you liked it.
You have a couple digital refractometers? Which models? Which one are you ok with?
Of course. I use a version of the More Beer sheet that I added a few features to, Attenuation, Rate, ABV, Estimated Completion and a graph. I feel the formula they use is pretty accurate although I do recall a podcast where somebody said they had a better one. Also, even if you didnt compensate for alcohol, you could still use a refractometer to see if fermentation is occurring. Once the numbers stop dropping, break out the hydrometer.
I use my analog refractometer for sparging, monitoring evaporation rate, OG, Fermentation and FG. For OG and FG, I always also use a hydrometer as well. Maybe Im lucky but my numbers are always right on. (At least within the error of how accurately I can read a refractometer or hydrometer.) For example, my current batch, an APA with an SRM of ~7, had an OG of 13.1 Brix by refractometer (1.0530 calculated) and a 1.052 hydrometer value (temp corrected 1.0533). I monitored the fermentation every ~12 hours until I had it hold steady at 6.6 for a few days (1.01074). Then I pull enough sample to check with my final gravity hydrometer where I got a reading of 1.0105 (temp corrected to 1.0108). Now I battled as to whether the 1.0105 was more of a 1.010 or a 1.0105 and finally decided on the latter. Same with the 6.6 as to if it was a 6.6 or a 6.5. Ive had the same experiences with darker beers and ones that also include sugar. I feel confident that I could use only the refractometer for everything, but since I have one and like to taste the sample I keep using it.
My question is, if Id have the same experience with a digital refractometer. Id like to have a value displayed and not have to second guess my squinting at the little lines. Ive also tried to hook up a camera but it wasnt worth the trouble.
True. I always try, in such cases, to mention what the source was but I'm sure I forget to do it sometimes.
I have an Atago hand held but I don't remember the model number. I'm 9500 miles from home right now so can't go look it up. The fancier instrument is a Reichert AR200. This is a really nice handheld refractometer which is accurate to 0.0001 nD or 0.1 Bx, allows you to turn ATC on and off, does multiple point calibrations etc. but other than that it basically the same as the Atago. IOW given the accuracy of the models the ATAGO is equally as useable in the brewery. Both are fine for the purpose for which they are designed. The Atago is pretty neat because it is small - slips easily into a shirt pocket.
Figured you probably did. Barring that there would be no way you could get agreement between hydrometer and refractometer reading.
I assume you are using narrow range hydrometers here.
Yes, I think so. The digital design is, IMO, more robust. You don't have to worry about interpretation of something you see, blurry boundaries aren't at issue, turbid or dark samples should be measurable and ATC can be done electronically rather than by the crude prism tilting mechanism of the conventional design (though as I noted earlier you really should do ATC manually when alcohol is present.
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