refractometer

[brumbrew]

Just been gifted this by my brew buddy. As he has a spare one. He works in engineering and milling so sugar is used in the 'suds' cooling liquid and has to measured.

It's older type Bellingham and Stanley made in Tunbridge Well UK.

Since I only now need a small drop to test sugar content I'm well happy. Although I have already cross checked the readings with two hydrometers and they came out with a tolorance of .002 so not much out.

All done at 20℃

It's the same as the one in this photo.

Anyone have any tips or things I may be overlooking?

My sky internet is down so I'm using my unreliable mobile data at the moment.

 

[W0nderW0man]

Okay this might sound stupid but is this the same type of refractometer that one uses to measure salinity? I've got a marine fish tank and have one of those.

 

[brumbrew]

Well when I put the sample on and held it to the light it said sugar % at the bottom.

Maybe there's two types.

My father used to have a 6ft marine fish tank when I was a kid ;-)

 

[Twostage]

I've got a similar one.

Advice - you need to use online calculators to use it. Before fermentation it is a simple multiply the brix reading be four to get OG. During fermentation the alcohol affects the reading so you need to put readings into a calculator.

Really convenient, though, as you can take mid brew readings using only a drop.

 

[ManseMasher]

One is for salinity (brine, or sea water) the other is for sugar. Unless I'm missing something I can get smashed by drinking the contents of the Dead sea....

 

[brumbrew]

Mine clearly says sugar % when you hold a sample up to the light.

Loving that I can sample with a drop. And I had to use an online calculator anyway.

I'm still learning ;-)

 

[hoptoit]

Has anyone used the ones on eBay that are around £10-£20? Are they any good for accuracy?

 

[johnnyboy1965]

Okay this might sound stupid but is this the same type of refractometer that one uses to measure salinity? I've got a marine fish tank and have one of those.

Yes it is, I also use one for my marine reef aquarium. As it says in the name it measures the amount of light that comes through whether it be salt or sugar

 

[johnnyboy1965]

Has anyone used the ones on eBay that are around �£10-�£20? Are they any good for accuracy?

If theyre calibrated correctly not much can go wrong with them

 

[johnnyboy1965]

PLEASE IGNORE ALL MY ABOVE POSTS
I bought a precision refractometer about 4 years ago. Just re-read the paperwork and it clearly states "For measuring SG/Salinity only"
Sorry
Apart from the post regarding calibration, they should be calibrated correctly.

 

[brumbrew]

No worries.

I took mine to work and accurately measured out 100ml of water and 10g of table sugar (to .001 of a gram may I add :-) )

Dissolved the sugar and tested a sample at 20℃ which I assume all these devices are calibrated to.

It measured 9.5% so I can assume that it is .5% 'out'

I also took gravity readings with a hydrometer last night of the last BIAB I did. and the hydro which I know measures .002 high read the same as the refractometer when the numbers are plugged into an online calculator.

So it appears that my hydro and refractometer have about the same % of error.

Still great that you only need a tiny sample.

 

[hoptoit]

Think I might give one a go for that price.
http://ebay.co.uk/sch/i.html?_mwBanner=1&geo_id=32251&MT_ID=10&crlp=87413543438_807&rlsatarget=aud-105106656306%3Akwd-15441653659&keyword=sugar+refractometer+brix&ul_ref=http%253A%252F%252Frover.ebay.com%252Frover%252F1%252F710-35648-5910-0%252F2%253Fmpre%253Dhttp%25253A%25252F%25252Fwww.ebay.co.uk%25252Fulk%25252Fsch%25252F%25253F_nkw%25253Dsugar%25252520refractometer%25252520brix%2526keyword%253Dsugar%252520refractometer%252520brix%2526crlp%253D87413543438_807%2526MT_ID%253D10%2526geo_id%253D32251%2526rlsatarget%253Daud-105106656306%253Akwd-15441653659%2526adpos%253D1o1%2526device%253Dm%2526poi%253D%2526loc%253D9046823%2526treatment_id%253D7%2526srcrot%253D710-35648-5910-0%2526rvr_id%253D971383643500&clk_rvr_id=971383643500&treatment_id=7&poi=&adpos=1o1&ul_noapp=true&_nkw=sugar+refractometer+brix&device=m&crdt=0

 

[Lawrence]

No worries.

I took mine to work and accurately measured out 100ml of water and 10g of table sugar (to .001 of a gram may I add :-) )

Dissolved the sugar and tested a sample at 20℃ which I assume all these devices are calibrated to.

It measured 9.5% so I can assume that it is .5% 'out'

I also took gravity readings with a hydrometer last night of the last BIAB I did. and the hydro which I know measures .002 high read the same as the refractometer when the numbers are plugged into an online calculator.

So it appears that my hydro and refractometer have about the same % of error.

Still great that you only need a tiny sample.

Don't forget that your calculation needs to take into account you now have more than 100ml.

 

[brumbrew]

My maths is terrible. I fought hard just to get a grade C in my GCSE exam many moons ago.

The online calculators have an in built equation to take into account the alcohol in the final reading. Which can throw off the reading. But no variable for the amount of wort.

Could you explain a little more?

 

[Lawrence]

My maths is terrible. I fought hard just to get a grade C in my GCSE exam many moons ago.

The online calculators have an in built equation to take into account the alcohol in the final reading. Which can throw off the reading. But no variable for the amount of wort.

Could you explain a little more?

Ok, simply put you started with 100ml and then added 10g of sugar, and for the sake of simplicity lets say that took the volume to 110ml.

You now have to work out the percentage of sugar in the solution and since you know what amount of sugar you have (10g) you divide that by the volume (110ml)

This gives 10/110*100(to make it a percentage) giving 9.09%

Following the same process, for 110ml to be a 10% solution it would have to contain 11g of sugar (10% of 110 is 11)

I suggest to check your refractometer again you start with your 10g of sugar, and then add up to the 100ml mark with your water and test that solution since that would be a 10% solution

I hope that helps.

 

[brumbrew]

Ok, simply put you started with 100ml and then added 10g of sugar, and for the sake of simplicity lets say that took the volume to 110ml.

You now have to work out the percentage of sugar in the solution and since you know what amount of sugar you have (10g) you divide that by the volume (110ml)

This gives 10/110*100(to make it a percentage) giving 9.09%

Following the same process, for 110ml to be a 10% solution it would have to contain 11g of sugar (10% of 110 is 11)

I suggest to check your refractometer again you start with your 10g of sugar, and then add up to the 100ml mark with your water and test that solution since that would be a 10% solution

I hope that helps.

I think.

I though I had made a 10% solution but I see where your going.

Maybe weigh the water instead of using a syringe. So 10g sugar vs 100g not ML of water. Would that be more like 10% ?

I'm expecting a certain degree of error both calibration and user ;-) but I was happy with .5% to be honest.

My calculations with help from a guy at work but .5 brix and .002 hydro at about the same error level.

 

[cheapbrew]

BB, Try this for the 10% solution stuff

http://www.sciencecompany.com/Preparing-Chemical-Solutions.aspx

 

[Lawrence]

I just went on ebay and bought one!

So to test it you need 10g of sugar and 90g of water (1ml weighs a gram) In fact since you need such a small sample to test you could probably use 1g of sugar and 9g of water.



You now have 100g (or 10g) of solution of which 10% is sugar.

I hope that is clearer.

 

[geetee]

B&S are a proper scientific company, dealt with them for years so this should be a good instrument f maybe dated.

As long as it is adjustable the only thing to do is to use distilled water and it should read dead on zero, the only calibration you should need.The 10% sugar solution is a test solution to check the calbration and should not be used for adjustment.

Do not add any hot wort even a small drop onto the glass plate as theoretically the heat can transfer and crack the internal prism.
Take a wort sample in a pipette and cool under the tap. Add a single drop and read.

Personally I only use a refractometer for monitoring wort up to the end of the boil and establishing OG, for this it is a quick easy reliable tool and the conversion of brix /gravity of x 4 is appropriate.

Monitoring beer during fermentation down to FG I prefer a suitable scaled hydrometer because no calculation is involved.

I have a £20 model of ebay and it has helped me enormously to monitor the gravity drops during sparging and establishing final OG and liquor back amounts, wouldn't be without it!

 

[brumbrew]

B&S are a proper scientific company, dealt with them for years so this should be a good instrument f maybe dated.

As long as it is adjustable the only thing to do is to use distilled water and it should read dead on zero, the only calibration you should need.The 10% sugar solution is a test solution to check the calbration and should not be used for adjustment.

Do not add any hot wort even a small drop onto the glass plate as theoretically the heat can transfer and crack the internal prism.
Take a wort sample in a pipette and cool under the tap. Add a single drop and read.

Personally I only use a refractometer for monitoring wort up to the end of the boil and establishing OG, for this it is a quick easy reliable tool and the conversion of brix /gravity of x 4 is appropriate.

Monitoring beer during fermentation down to FG I prefer a suitable scaled hydrometer because no calculation is involved.

I have a £20 model of ebay and it has helped me enormously to monitor the gravity drops during sparging and establishing final OG and liquor back amounts, wouldn't be without it!

I'd never thought about monitoring the output of the sparge water. Will do this next time.

I'm lead to believe that these models come with a temperature correction strip.

Two metals that differ in expantion under heat. As to adjust the lens.

I always put an ambient sample on the lens.

I think I can find good use for this. And it was free!!!!