I have a Milwaukee MA887 and I have had a lot of trouble using it. I switched back to calibrating my refractometer daily and using that. I would like to get the Milwaukee working and be able to trust it.
I have been calibrating the unit with 0tds RODI. I zero it out and then I read the RODI water and it has 1ppt. I then ready my refractometer calibration solution which reads from 36-37ppt. This is close and 36 is within the 1ppt margin of error. I then read my tank water and get completely different results from my calibrated refractometer. The Milwaukee typically reads high. 37- 38 ppt. This occurs consistently.
My other issue is that I kept the refractor meter in the basement under the sump. Its cold down there. I then pulled it out and used it and it was reading crazy numbers. All over the place. I left the sample in the lens, moved the unit upstairs where it was 70F and took readings every 5 minutes and it slowly lowered the salinity to a more reasonable reading. After 2 hours it was reading as close as it typically does to the refractometer. I know these units should compensate for temp differences but it does not appear to do that. My concern is my RODI water is stored in the cold basement and the tank water is 78 when tested. I keep the Milwaukee in the basement near the sump because that is where my storage and testing is completed.
My last concern is that there is a margin of error of 1ppt. So I keep my reef at 34ppt so I have wiggle room either way. If I get a reading of 33ppt, it could be 34ppt or 32ppt. Likewise if I get a reading of 35ppt. This is a large margin of error when we are working within a 5ppt window. Maybe all the other refractometers have similar margin of errors and I don’t worry about it because I am using my eye to make the reading, but it makes me nervous to hang up the conventional refractometer with all these inconsistencies.
I have been calibrating the unit with 0tds RODI. I zero it out and then I read the RODI water and it has 1ppt. I then ready my refractometer calibration solution which reads from 36-37ppt. This is close and 36 is within the 1ppt margin of error. I then read my tank water and get completely different results from my calibrated refractometer. The Milwaukee typically reads high. 37- 38 ppt. This occurs consistently.
My other issue is that I kept the refractor meter in the basement under the sump. Its cold down there. I then pulled it out and used it and it was reading crazy numbers. All over the place. I left the sample in the lens, moved the unit upstairs where it was 70F and took readings every 5 minutes and it slowly lowered the salinity to a more reasonable reading. After 2 hours it was reading as close as it typically does to the refractometer. I know these units should compensate for temp differences but it does not appear to do that. My concern is my RODI water is stored in the cold basement and the tank water is 78 when tested. I keep the Milwaukee in the basement near the sump because that is where my storage and testing is completed.
My last concern is that there is a margin of error of 1ppt. So I keep my reef at 34ppt so I have wiggle room either way. If I get a reading of 33ppt, it could be 34ppt or 32ppt. Likewise if I get a reading of 35ppt. This is a large margin of error when we are working within a 5ppt window. Maybe all the other refractometers have similar margin of errors and I don’t worry about it because I am using my eye to make the reading, but it makes me nervous to hang up the conventional refractometer with all these inconsistencies.
