[musseldoc]

Anyone have trouble with their refractometer losing its calibration?  It seems every time I go to use mine, it seems to be off by ~1 Brix.  At first I thought it was differences in the DOC of the source water I was using, but then I started calibrating with distilled water and the problem still exists.  Basically, I clean with tap, dry, then place 3 drops of distilled on the prism, then turn the dial so the blue line crosses at zero.  Seems simple enough.  Yesterday, I calibrated at the beginning of the brew day and by the end of the day it was off by 1 Brix again.  I have tried everything short of throwing it to intentionally try to get it to lose its calibration with no success.  But, sure as I leave it sit for a day, it's off again.  Is there a locking mechanism or something that I need to use once I turn the dial when I calibrate?  Any ideas on whats going on? 

[Stevie]

I have read in Amazon reviews that the cheap ones will fall out of calibration. So far mine is good.

[erockrph]

I got a real cheap dual scale one on Amazon and it's almost always dead-on. The water you're using to calibrate is at the proper temp, right?

[HoosierBrew]

I must be lucky. I bought one of the $40-50 ones from Amazon and the thing is rock solid. I check calibration with distilled every time and it doesn't drift. And the readings are consistent. I've heard stories of readings being all over the place with some, but I check each sample 2 or 3 times to check consistency and it's good there. I still use a hydrometer for FG, but I love the thing.

[David Lester]

Temperature variations might be your issue. Check first to see if your refractometer works correctly at any temperature. By the way, why is being off by 1 point a bad thing? Every meter has its variations.



Cheers,
dLester

[tommymorris]

Temperature variations might be your issue. Check first to see if your refractometer works correctly at any temperature. By the way, why is being off by 1 point a bad thing? Every meter has its variations.



Cheers,
dLester

1 Brix is about 4 specific gravity points.  I think that is more than minor variation. That's 10% for a 10 Brix brew. Most measuring tools are more accurate than +/- 10%.

[reverseapachemaster]

Does the refractometer always stabilize at exactly the same point 1 brix low or high? If so, I'd think about not fighting against the refractometer and just add/subtract one brix in my calculation to determine gravity rather than recalibrating each time you use it.

[musseldoc]

I definitely thought about temperature.  I calibrated yesterday morning when it was ~55F, then it was off calibration after the air had cooled to ~35F that evening.  So, I held the refractometer in my hand for several minutes to warm it back up, and the calibration was still off.  For OG, 1 brix isn't such a big deal, but for FG it affects the calculation for FG by quite a bit. 

[a10t2]

If it's one of the cheap Chinese ones, I think the tolerances on the ATC springs are not great, and that's why some people have issues. Unfortunately, mine is always dead on, so I haven't done any troubleshooting on the problem.

I'd say just bite the bullet and spend the $25 for a new one. If an instrument can't be calibrated, it isn't useful.

[Slowbrew]

Sorry to hear about your issue. 

I bought mine years ago (on ebay, I think) and have never had to adjust it.  I'm feeling pretty luck at this point.

Paul

[blatz]

been using mine for about 5 years now, and i check it with a hydro everytime and i've never messed with the calibration since the first month or two since i bought it.

[denny]

I have 2 and I've given up on using them.  No matter how I calibrate, I can't get them to agree with each other or my hydrometer.

[blatz]

I have 2 and I've given up on using them.  No matter how I calibrate, I can't get them to agree with each other or my hydrometer.

i heard they don't work in oregon 

[denny]

I have 2 and I've given up on using them.  No matter how I calibrate, I can't get them to agree with each other or my hydrometer.

i heard they don't work in oregon 

So THAT'S it!

[yso191]

I brewed an American Brown Ale today.  I often don't take a preboil gravity reading, but I thought I would today.  I stirred the wort in the boil kettle after sparging and took a sample.  My refractometer read 1.032!  It should have been 1.041.  So I'm thinking about adding DME.

But I thought I should take another sample and reading.  Stirred again, drew my sample and it read 1.043.  Nice.

But I thought I better get 2 samples alike so I stirred again, sampled... and it read 1.055!

I'm thinking it would be immoral for me to sell the refractometer.

Oh.  With the hydrometer my OG was 1.052.  Beersmith predicted 1.051.