Pro Grade Refractometer Atago PAL-1Friday, June 14th, 2013
The Atago PAL-1 is a professional grade digital refractometer that we got to test out over the past few brew sessions. Compared to my $40 refractometer from Amazon, it is a night and day difference. The PAL-1 is super accurate reading to reading, varying only +/- 0.05 Brix. Contrast that with my cheap-o refractometer which reads +/- 0.6 Brix sample to sample, making it near useless since I have to average 6+ samples to get a good idea of the gravity.
For anybody who brews beer often the PAL-1 is a real treat to use. I can see this unit being an essential tool at any pro brewery. The measurement range is from 0 to 53 Brix, plenty wide. It is water resistant, so you can rinse it off in the sink. It even floats (but I didn’t test that).
Unlike a standard analog refractometer, the PAL-1 is digital. It requires two AAA batteries and works from the palm of your hand. Just put a couple drops of wort in the sample area and hit the start button. It only takes a second for the reading to come up.
Like all refractometers the PAL-1 needs to be calibrated with water before each use. The unit is simple to operate – there are literally just two buttons (start = take reading, zero = calibrate with water). The manual provides detailed info about how to operate it and the various on screen codes that come up. The only trouble I ever had was skipping the calibration or not putting in a large enough sample (both user error). I found that 2-3 drops does the trick, with a wide margin of error provided the minimum sample size is met. The unit reads best at 59F, but has automatic temperature correction (ATC).
Like all refractometers, the PAL-1 does not correct for the presence of alcohol which throws off the reading. This is not a showstopper for me because Brewer’s Friend corrects for this both in the Brew Log entry screen, and in our stand alone Refractometer Calculator.
I found the FG numbers the PAL-1 and my old school refractometer were giving lined up reasonably well with a hydrometer after applying alcohol correction. Still, FG readings should be taken with a hydrometer. Refractometers are best suited for OG readings, and taking readings during the mash, or at preboil.
Technical Explanation of How a Digital Refractometer Works:
“Light emitted at an angle from a point source underneath the prism toward the sample liquid enters the boundary surface at multiple angles. Depending on the refractive index of the sample, light may be transmitted (refracted) or reflected. For example, water has a low refractive index, and therefore, light is refracted at a small angle of incidence. Likewise, light traveling through a sample of high refractive index is refracted at a large angle of incidence. Refractive index is proportional to critical angle, the largest angle of incidence for with refraction can still occur before incident light is totally reflected. A boundary line separating light and dark fields appears at the critical angle. The location of this boundary line is detected by the light receiving sensor and the refractive index is calculated.”
- Atago Catalog
Here is a page that explains more about how it works.
Atago’s website and ordering information:
www.atago-usa.com (main page)
http://www.atago-usa.com/PAL-1-Pocket-Refractometer-p176.html (PAL-1 product page)
http://www.atago-usa.com/PAL-Plato-p437.html (PAL-Plato product page)
But wait, there’s more…!
Atago granted our readers a special discount code! Brewer’s Friend readers can save 5% off a PAL-1 or PAL-Plato. Valid through 2013.
Promo Code for web store: BREWPAL
Post by Larry
(Brewer’s Friend received an evaluation PAL-1 demo unit.)