How to properly use milwaukee digital refractometer

scurvy dawg · Nov 21, 2017

skiergd011013 said:
Mine is frustrating me a bit. It fluctuates between 1.025 and 1.026. The same sample on the prism will say 1.026, then 1.025 a minute later. I just did a w/c and tried to mix new water to 1.025. It said 1.026, so i added a bit of fresh to it. It then tested .025, i did a second test to confirm, and it was back to .026. I re-read the instructions, and followed them. I calibrated to zero with the included solution, then took my sample and waited a minute for temp to equalize. No matter what i do, it fluctuates. I finally just used the water. So basically all i know is that it was either .025 or .026. Is this normal and does this happen to you? I feel like i dont know for sure what my salinity is.

According to the manual, the unit is accurate plus/minus .002 so I think it would be perfectly normal to get the two readings you are getting.

outeastreefer · Nov 21, 2017

I also use the milwaukee digital hydrometer. To calibrate I use a Tropic Marin atm51002 precision hydrometer. seems very accurate.

outeastreefer · Nov 21, 2017

Forgot I use the solution from Randy Holmes-Farley. Thanks Randy!!

7hogwarts · Nov 21, 2017

I have a Milwaukee unit as well. ( I got some very poor responses from them on calibrating/cleaning) Randy set things right. In any event, I like the unit. I cross check it occasionally with my hand held refractometer and a glass floating hydrometer. It's all good.

skiergd011013 · Nov 21, 2017

Thanks all. I didnt expect such a huge response. I guess this thing is very popular. I will check mine with the seawater calibration fluid and report back.

jd371 · Nov 21, 2017

Just ordered one and have it coming next week. My refractometer has been drifting too much lately and not holding the calibration. In the past my refractometer would be stable and hold the calibration for a while. I always calibrate before testing and for the most part it would be just a little off, if any. Recently it's been way off and needing a big adjustment every time. Last night after calibrating I tested the sample water, it read 1.023 instead of 1.025 like it's always been. So I calibrated again and it was out already after the initial calibration a few minutes earlier, even after waiting a minute each time for the refractometer to temperature adjust. That was the last straw and I ordered the Milwaukee.

skiergd011013 · Nov 21, 2017

Well, i just spent some time playing with it. I calibrated to zero, and then checked it with the included 1.025 solution. It measured 1.025 twice in a row. So i guess my unit is dead on. Its saying my tank is 1.025 to 1.026. I am just going to use and rely on it.

sghera64 · Nov 21, 2017

roberthu526 said:
I have this unit and it is pretty accurate. I calibrate with RO water and confirm with 1.025 solution and it’s always dead on.

+1

FlyinBryan · Nov 21, 2017

I’m tagging along on this. My handheld light refractometer says my tank is right at 1.0265 but the Milwaukee says 1.035, no matter how many times I calibrate it. I am getting ready to return it.

Randy Holmes-Farley · Nov 22, 2017

FlyinBryan said:
I’m tagging along on this. My handheld light refractometer says my tank is right at 1.0265 but the Milwaukee says 1.035, no matter how many times I calibrate it. I am getting ready to return it.

Presumably they will disagree on a 35 ppt standard as well, and you can tell which, if either, is accurate.

Lifer · Dec 7, 2017

skiergd011013 said:
the solution mine came with says 1.025 on the bottle. Yours is 1.026?

The funny part is that the bottle states 1.025 however everytime I calibrate and try it mine shows 1.026!

skiergd011013 · Dec 7, 2017

Lifer said:
The funny part is that the bottle states 1.025 however everytime I calibrate and try it mine shows 1.026!

I have warmed up to my meter now. It is working great. When calibrated to zero, it reads exactly 1.025 with the included solution, everytime. I always calibrate to zero with each use, rinse the prism with the water to be tested, then get my sample, and wait about a minute for the temp to equalize. after i am done with it, I run the prism under the tap to rinse so theres no salt residue to throw off my measurements next time. Its been great and I maintain my tank at 1.025 with it no issue.