I recently purchased a set of 3 narrow-range, laboratory-grade hydrometers from Northern Brewer for ~$60. I love the idea of greater accuracy, and easier to read Hydrometers.
I brewed yesterday. I checked the OG three ways. My refractometer said 1.085; the old standard hydrometer said the same. The new ‘lab grade’ hydrometer read 1.080.
So I got some distilled water and the low range ‘lab grade’ hydrometer. It read 0.999. The old regular hydrometer read 1.000, as did the refractometer.
I’ll do a test on the other two Hydrometers with some sugar water of a known gravity, but so far I am unimpressed.
Read up on making your known solution of sugar water. You can dilute to make it half the %, then half again easily.
The lab grade was off .01 with water, so the 0 is off a know amount. The difference with the old hydrometer and the refractometer was bigger, so there is a gain difference somewhere.
Keep us posted on what you find. I need to do the same someday soom.
In a 1.085 solution:
The refractometer showed 1.085
The high range hydrometer showed 1.083 (I suspect yesterday’s reading below was incorrect)
The full range hydrometer showed 1.082
In a 1.040 solution:
The refractometer showed 1.041
The mid-range hydrometer showed 1.041
The full range hydrometer showed 1.041
In RO water:
The refractometer showed 0.000
The low range hydrometer showed 0.999
The full range hydrometer showed 0.000
The bottom line for me is that when measuring OG I am going to stick with the refractometer. When measuring FG I’ll go with the low range hydrometer just because it is easier to read, and adjust up 0.001.
I love being exact, but it is homebrew so no big deal either way I’m sure.
At what temperature did you take your readings? Density varies with temperature. Hydrometers are calibrated to read 1.0 with distilled water at a specified temperature. Your hydrometers should have shipped with slips of paper that give you a list of temperature corrections.