jeff williams
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I've discover a solution to my Refractometer not holding its calibration. My unit is one similar to the BRS unit and is a brine/salinity model in its instructions it say to calibrate at 69degs with RO water as you know this is not the way to go! Randy has a great post on Refractometers here you should read it.
Refractometers And Salinity Measurement
By Randy Holmes-Farley, Dec 9, 2015 | 1.5K Views | Reef Chemistry
I struggled to come to terms with my Refractometer and just didn't trust the reading.
Hers how I corrected it.
First buy a calibration fluid and don't worry about the .35 ppm@77degs hoopla on the bottle. What's important is that it's a known salinity that is close to were are water salinity is in our aquariums.
Second store your Refractometer in the room you plan to use it, this doesn't have to be were your reef is at. What's important is the room has a temperature that is stable it dosent fluctuate very much.
Third let the Refractometer and calibration fluid acclimate to this room, then calibrate it. I usually store mine in its case in my qt room that maintains 72 degs. Don't worry about the instructions that say to calibrate at 69 degs unless you plan to use it in a room that is 69 degs.
Fourth suck up a small water sample in the pipette take it into the room where the Refractometer is stored and let it acclimate to this room. A small sample will acclimate in 5-10 min during this time I like to remove my Refractometer from its case and let the crystal adjust to the temp of room just for piece of mind.
Fifth once acclimated drip the sample on the Refractometer close the cover and let sample acclimate to the crystal temp 30 seconds or so then read your sample point the crystal to a good light source while reading.
This sounds like a long process but it really only takes a few minutes once the Refractometer is initially calibrated.
You might say well my Refractometer is a ATC model well so is mine and I found this method much more accurate. Also some people try to warm there calibration fluid this won't help because the Refractometer is a different temp the fluid will just acclimate to the crystal.
The important thing I found is that everything is the same temperature that the Refractometer was calibrated at. Hope this helps people with the same problem I was having.
Refractometers And Salinity Measurement
By Randy Holmes-Farley, Dec 9, 2015 | 1.5K Views | Reef Chemistry
I struggled to come to terms with my Refractometer and just didn't trust the reading.
Hers how I corrected it.
First buy a calibration fluid and don't worry about the .35 ppm@77degs hoopla on the bottle. What's important is that it's a known salinity that is close to were are water salinity is in our aquariums.
Second store your Refractometer in the room you plan to use it, this doesn't have to be were your reef is at. What's important is the room has a temperature that is stable it dosent fluctuate very much.
Third let the Refractometer and calibration fluid acclimate to this room, then calibrate it. I usually store mine in its case in my qt room that maintains 72 degs. Don't worry about the instructions that say to calibrate at 69 degs unless you plan to use it in a room that is 69 degs.
Fourth suck up a small water sample in the pipette take it into the room where the Refractometer is stored and let it acclimate to this room. A small sample will acclimate in 5-10 min during this time I like to remove my Refractometer from its case and let the crystal adjust to the temp of room just for piece of mind.
Fifth once acclimated drip the sample on the Refractometer close the cover and let sample acclimate to the crystal temp 30 seconds or so then read your sample point the crystal to a good light source while reading.
This sounds like a long process but it really only takes a few minutes once the Refractometer is initially calibrated.
You might say well my Refractometer is a ATC model well so is mine and I found this method much more accurate. Also some people try to warm there calibration fluid this won't help because the Refractometer is a different temp the fluid will just acclimate to the crystal.
The important thing I found is that everything is the same temperature that the Refractometer was calibrated at. Hope this helps people with the same problem I was having.
