Calibrating Refractometers and Hydrometers

All equipment-related discussion

Moderator: Brandon

User avatar
Brody
Assistant Brewer
Posts: 326
Joined: Sat Nov 14, 2015 11:30 pm
Location: Philadelphia, Pennsylvania

Calibrating Refractometers and Hydrometers

Postby Brody » Tue Jan 10, 2017 1:48 pm

I've been feeling less than confident in some recent gravity readings.

A relatively cheap refractometer (https://www.amazon.com/gp/product/B00CO ... UTF8&psc=1) I bought almost 2 years ago has been my main tool. Yesterday I calibrated it to 0 with distilled water but was hoping to check it on the other side. I heard a sugar water solution would be no good for some reason? The 28g sugar to 176g distilled water read way higher - when I went to calibrate to 1.048/12 based on that solution my distilled water reading was obviously way to low.

My hydrometer seems to be a mess. It reads <1.000 SG with distilled water but when I tried the solution of 28g table sugar to 176 Distilled Water (supposed to be 1.048/12 based on http://www.eckraus.com/blog/calibrate-h ... hydrometer) I read well above 1.048 (in the mid 1.050s). Not sure if that means I should junk it or plot a chart.

Any inputs on good reliable tools for measuring gravity and calibration tips?
User avatar
Brody
Assistant Brewer
Posts: 326
Joined: Sat Nov 14, 2015 11:30 pm
Location: Philadelphia, Pennsylvania

Re: Calibrating Refractometers and Hydrometers

Postby Brody » Tue Jan 10, 2017 1:54 pm

User avatar
lupulus
Apprentice Brewer
Posts: 204
Joined: Wed May 11, 2016 8:35 pm

Re: Calibrating Refractometers and Hydrometers

Postby lupulus » Tue Jan 10, 2017 4:27 pm

12g of sugar mixed with 92.84g of distilled water will weigh 104.84g and yield a 12% sugar solution at 20C.
Incidentally, you should have 100mL of solution at 20C. This is what in chem/biochem is called a 12% w/v sugar solution.
For 176g of distilled water, you would need 22.749g of sugar to get a 12% sugar solution
It read higher because it was higher :-)
Ich trinke Bier nur an Tagen die mit G enden , und Mittwochs
User avatar
Brody
Assistant Brewer
Posts: 326
Joined: Sat Nov 14, 2015 11:30 pm
Location: Philadelphia, Pennsylvania

Re: Calibrating Refractometers and Hydrometers

Postby Brody » Tue Jan 10, 2017 4:29 pm

lupulus wrote:12g of sugar mixed with 92.84g of distilled water will weigh 104.84g and yield a 12% sugar solution at 20C.
Incidentally, you should have 100mL of solution at 20C. This is what in chem/biochem is called a 12% w/v sugar solution.
For 176g of distilled water, you would need 22.749g of sugar to get a 12% sugar solution
It read higher because it was higher :-)


Thanks guess that EC Krauss is an idiot!
User avatar
Brody
Assistant Brewer
Posts: 326
Joined: Sat Nov 14, 2015 11:30 pm
Location: Philadelphia, Pennsylvania

Re: Calibrating Refractometers and Hydrometers

Postby Brody » Tue Jan 10, 2017 4:47 pm

Well I measured that out - my refractometer said 1.044 and my Hydrometer said 1.038.

That makes the Hydrometer low on both Distilled and Sugar Solution tho by different amounts. Wonder if I can trust my refractometer so long as it's reading 0/1.000 with distilled?
User avatar
Brody
Assistant Brewer
Posts: 326
Joined: Sat Nov 14, 2015 11:30 pm
Location: Philadelphia, Pennsylvania

Re: Calibrating Refractometers and Hydrometers

Postby Brody » Tue Jan 10, 2017 4:59 pm

Just busted out a bottle tea. 547ml bottle with 42grams of sugar. So ~7.7% extract. Put a drop on the Distilled calibrated refractometer and it read at 1.031/7.7%. So I guess I'm good to rely on this (of course using the post-fermentation calcs) and forget the hydrometer.
User avatar
lupulus
Apprentice Brewer
Posts: 204
Joined: Wed May 11, 2016 8:35 pm

Re: Calibrating Refractometers and Hydrometers

Postby lupulus » Tue Jan 10, 2017 6:25 pm

Glad you figured it out :-)
Ich trinke Bier nur an Tagen die mit G enden , und Mittwochs
User avatar
Ancient Abbey
German Brewing
Posts: 1191
Joined: Tue Dec 22, 2015 8:23 pm

Re: Calibrating Refractometers and Hydrometers

Postby Ancient Abbey » Sun Feb 26, 2017 8:29 am

My handheld refrac wouldn't hold a zero. Poor design allowed the scale to shift with temperature changes. I eventually gave up and bought a digital...
- The best do the basics better -
User avatar
Brody
Assistant Brewer
Posts: 326
Joined: Sat Nov 14, 2015 11:30 pm
Location: Philadelphia, Pennsylvania

Re: Calibrating Refractometers and Hydrometers

Postby Brody » Sun Feb 26, 2017 5:47 pm

Yea, mine seems to need to be recalibrated frequently. Any recs for a good digital?
Bryan R
Braumeister
Posts: 882
Joined: Tue Oct 13, 2015 9:27 pm

Re: Calibrating Refractometers and Hydrometers

Postby Bryan R » Sun Feb 26, 2017 7:41 pm

I have used this one for ages.
http://www.testequipmentdepot.com/milwaukee/refractometers/ma871.htm


Sent from my iPhone using Tapatalk

Who is online

Users browsing this forum: No registered users and 1 guest