Kessil

I need to replace my refractometer

I am using a Marine Depot refractometer which is a POS. I have to constantly calibrate it. I calibrate one day and the next day it is .005 off! When I first purchased it without calibrating it, it was .020 off and I killed all of my CUC. :(

Anyone know of a accurate refractometer? Or maybe should I get one of those Pinpoint salinity monitors?
 
I think it is a good idea to calibrate your refractometer every time you use it. Temperature changes can bring about inaccuracies. I almost bought that same one as you, but in the end decided to buy the cheapest Captive Purity. Calibrated it with some test fluid I got from the last meeting but, well, since I don't have my tank set up yet I can't exactly comment on much more. There are refractometers that have automatic temperature compensation but obviously they are more expensive.
 
My $35 generic ebay one supposedly has automatic temp comp (ATC). Came in calibrated and still is. with ATC you gotta let it sit for 30 seconds before you take the measurement
 
As Tim stated they are temperature sensitive, I've used the Marine Depot for a while now without issue, actually I'm on my second one. IIRC they are best used at 77º, lower temps will case it to read a higher gravity than the tank actually is.
 
Mine gets under my skin too, but thank god for the BAR standard. I actually keep mine literally next to the tank (and standard too) so they're at the same temp - which just happens to be at 77 :)
 
My refractometer is the ATC version and I leave the water on there for 30 seconds. I've also read on RC where people have had mix results with there MD refractometer.
 
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