Refractometers Calibration

[Jeff Buzz]

Having seen many posts on calibration of refractometers and what to use to check it is set correctly (also going through the process myself)

How about this for a KISS method.....

Why not test against capped off honey that should be around 16/18% and set refractometer against this.

Then check any suspect uncapped areas to see if it matches.

I have lots of frames 60% capped but they still dont pass the shake test as the bees are bringing nectar in and sticking it anywhere it seems
So did a test last night

Shook out a frame only a little liquid came out tested at 27%
Capped honey tested at 17%
Uncapped honey that did not shake out ....16%

So I have lots of frames like this I may shake them out over hive until they stop perhaps only 3 shakes then extract what is left.

Now is this a plan????

 

[oliver90owner]

Checking to possibly no better than 2%? Forget it.

Being sensible about what to extract and re-arranging frames after some consideration of the problem might be a good choice to overcome the problem.

First question might be: Why extract at the end of June?

 

[Jeff Buzz]

Thanks for you reply Oliver

The reason I want to extract is I need more room every thing I have is full of honey and I am hoping to take advantage of a nearby Borage field that should be in flower soon.

The point of above is that if you have capped honey then you would probably be happy to extract without testing it moisture content, if you compare the capped to the uncapped and its the same then thats useful and perhaps of more relevant than using. golden syrup as discussed previously.

I am really a beginner at all this so any tips on getting honey capped would be very much appreciated. I have tried giving them more room but they just fill it with honey.

 

[oliver90owner]

Jeff,

The simple reason for using olive oil as a standard is that it is stable. Stored carefully, its refractive index will be the same next year as this.

The only thing you need to be confident is that your refractometer is reading correctly at present. Unused and un-fiddled with is likely a good starting point, but not completely fool-proof. Taking the reading for the oil then gives you a good stable base. As long as the instrument reads the same next year, it will be calibrated the same as this year. Nothing more.

I will PM you later with a relatively simple test procedure that will only determine if your refractometer is currently accurate. If it is, then you check the reading for your best olive oil and retain a sample of that oil for future checks or recalibration.

RAB

 

[enrico]

If you remember RAB, when I received my refractometer the instructions were so garbled that I mistakenly tried to calibrate it using distiller water. That did not work but by then I had moved the calibration from the factory setting. I think I am erring on the side of caution with my present readings but would love to know how I can re calibrate it now to get it correct so that I can then use oil for the future. Maybe someone out there could send me some oil with a known calibration value!
Ever hopeful
E

 

[oliver90owner]

I mistakenly tried to calibrate it using distiller water.

Not to worry. Just PM HM Honey. He assures me, and everyone, that is the way to do it. He must know something I don't.

See thread: http://www.beekeepingforum.co.uk/showthread.php?t=29464&page=2

I will send you a copy of my PM at same time as Jeff. It will take me a while. Note this will only be to check that it is reading correctly.

RAB

 

[Jeff Buzz]

Thanks Oliver I think I am right with the calibration but would love to check it.

Thanks very much for taking the time to send it over

Cheers Jeff

 

[Tonyatcwfarm]

Could you reccommend a good make of refractometer to buy pls.

 

[BeeJayBee]

Mine came from Gain Express (or similar name) on Ebay. Make sure you buy a honey refractometer, because there are others available that won't work with honey.

 

[Erichalfbee]

To check just make up a known sugar solution within the range of your refractometer?

 

[enrico]

To check just make up a known sugar solution within the range of your refractometer?

Oh! What at a simple idea! Wish I had thought of that!
Thanks, will try it
E

 

[burren]

I know it is very late... but i dont understand ,what does " to check just make up a known sugar solution within the range of our refractometer mean?" thanks

 

[Erichalfbee]

OK.
Look at the range your refractometer measures.
20% water content should be there.
Make up an 80% sugar solution....which will have 20% water.
Check that your refractometer does actually say 20%
VOILA!

 

[Marton]

When we talk of 18% is it w/w, v/v or w/v?

I presume it is w/w although that should for water be the same as w/v.



Sent from my iPhone using Tapatalk

 

[Gilberdyke John]

When we talk of 18% is it w/w, v/v or w/v?

I presume it is w/w although that should for water be the same as w/v.



Sent from my iPhone using Tapatalk

Does sugar contain water of crystallisation?

 

[itma]

% is weight %.

OK.
Look at the range your refractometer measures.
20% water content should be there.
Make up an 80% sugar solution....which will have 20% water.
Check that your refractometer does actually say 20%
VOILA!

However, at 20ºC, sucrose (ordinary table sugar) maxes out at 67% - water won't hold more. (Which is why folks who wrongly take "2:1" as meaning using the same weight units for sugar and water get crystallisation on cold nights!)


There is a lot of misunderstanding about "calibration".
The instrument, as purchased, should NOT need calibration.

There is no point whatsoever in upsetting the factory calibration unless you have reason to doubt its accuracy AND you have the means to be more accurate.

I believe there are three possible routes to simple calibration at home
1/ If ordering from Hong Kong via eBay, pay the £4 or so extra for the glass calibration block and its contact oil.
2/ Go to the pharmacy and buy a small bottle of Liquid Paraffin BP, as suggested by Thornes.
3/ Using any available single jar of runny honey, adjust your refractometer to read exactly the same as a "known-accurate" instrument. Where to find a "known-accurate" instrument? Two suggestions - either your Association's honey show judge or visit Trading Standards.

 

[Erichalfbee]

Yes....that's a problem. Typing without thinking. I'm not a chemist and my A level chemistry is 40+ years old..
I've never calibrated mine.


PS apologies to all who have up all night stirring....... trying to make an 80% sugar solution

 

[jd101k2000]

Just found this article from a company that sells refractometers on how to calibrate a refractometer.

http://doclibrary.com/MSC167/PRM/Calibration Verification4435.pdf

 

[oliver90owner]

Not a lot of good for an 'ATC' model? That is for an accurate precision instrument. I do not place these little hand-held Chinese offerings in that category! Convert the RI to water content, and if to better than nearest 1/2 perent, that is rough and ready enough.

As an aside to Erichalfbee's suggestion, one could use glucose or fructose as your sugar, or partofvit. Remember, honey is not (or should not be) a'solution of sucrosevin water. Even the scale on the refractometer is likely not in degrees Brix, but a compromise of averages found from the real world.

 

[johnandyrob]

Having seen many posts on calibration of refractometers and what to use to check it is set correctly (also going through the process myself)

How about this for a KISS method.....

Why not test against capped off honey that should be around 16/18% and set refractometer against this.

Then check any suspect uncapped areas to see if it matches.

I have lots of frames 60% capped but they still dont pass the shake test as the bees are bringing nectar in and sticking it anywhere it seems
So did a test last night

Shook out a frame only a little liquid came out tested at 27%
Capped honey tested at 17%
Uncapped honey that did not shake out ....16%

So I have lots of frames like this I may shake them out over hive until they stop perhaps only 3 shakes then extract what is left.

Now is this a plan????

Try changing the time of your tests. Do them first thing before bees have time to bring in fresh nectar and have had all night to evaporate water off. Or even after a day of rain.