Issues with Milwaukee MA887 Refractometer

[Biglurr54]

I picked up a Milwaukee MA887 refractometer as I have heard such good things about it. I have had nothing but trouble with the unit. My issue is that I calibrate with fresh 0 tds RODI water and then check with refractometer solution and it is consistently off. (too high) The other issue is that I keep the instrument in the basement at my sump/aquarium work bench. The basement is a cold drafty basement which is 50-65 degrees depending on the season and outside temp. I have noticed that when I try to get a reading from my tank, the instrument shows one number, then I wait 5 minutes and read the same sample and it shows a completely different number. The only variable is the temp change.


Is there a working temperature range for the ATC portion of the instrument?


Is there a reason it does not accurately read natural seawater refractometer calibration solution accurately?


Should I bring the RODI water up to 78 degrees (tank water temp) before using it to calibrate the machine?

 

[Larry L]

You should always try to calibrate with a solution that is close to what you will be trying to measure, if the device will let you.

 

[Snoopy 67]

Calibrate the unit with solution, NOT RO water. The closer to what you want to measure the better.

 

[Thor2j]

I talked to milwaukee and they said rodi water will not provide correct results, must be distilled.

Secondly for those saying use a solution the button to calibrate is ZERO so how do you use a solution??

I've had zero problems with mine in 3 years. Always calibrate before using . It should also automatically adjust for temp.

 

[Thor2j]

Calibrate the unit with solution, NOT RO water. The closer to what you want to measure the better.

How??

 

[SeaDweller]

I just used mine this morning and after calibrating with the water and then checking the 1.025 sample, it's on point. Checked my DT salinity and all is well.

I hope you get yours figured out. Are the batteries new?

 

[Biglurr54]

Yes new battery.

Have any of you tested against a calibrated eye refractometer?

My MA887 is consistent when it's at room temp (70 degrees). It does not calibrate and it does not match a calibrated eye refractometer but it is consistently off the same amount when at 70 degrees.

 

[Thor2j]

Yes new battery.

Have any of you tested against a calibrated eye refractometer?

My MA887 is consistent when it's at room temp (70 degrees). It does not calibrate and it does not match a calibrated eye refractometer but it is consistently off the same amount when at 70 degrees.

Something is wrong with yours.

 

[vinnyol]

I having the issue that reads air when I am calibrating or testing salinity. I have removed battery and still reads air. I cover the entire area of either calibration solution or RO water. This unit is 3byrs old.

 

[Nhjmc]

I just ordered one off eBay and it’s not giving a reading. So frustrating. I was so excited to get and use this as only read all but good things about it.

 

[MichaelReefer]

Calibrate the unit with solution, NOT RO water. The closer to what you want to measure the better.

Calibrated mine with RO water, perfect at 1.026 with solution.

 

[Nhjmc]

I’ve tried both then read Online to use distilled water to cal so ran to store for it now showing “lo” on display. Ughhhh. This is what I get for trying to save a buck but to my defense it was marked as “new” on eBay.

 

[kartrsu]

I have calibrated my with RODI water and it reads the salt spot on. I make my own calibration solution using Randy's formula. Got to have a good scale.

Use 3.65 weight percent sodium chloride solution to match 35 ppt (sg = 1.0264). It can be made by dissolving 3.65 grams of sodium chloride in 96.35 grams (mL) of purified freshwater.

DIY Salinity calibration solutions

Randy, In light of another post on calibrating a conductivity meter, I decided to give it all a shot on my own system. I read through your article on DIY salinity calibration (http://www.reefkeeping.com/issues/2004-06/rhf/) and have a few questions for my simple brain. 1. Is the Brand MORTON...

www.reef2reef.com

 

[HuduVudu]

Calibrate the unit with solution, NOT RO water. The closer to what you want to measure the better.

Milwaukees always calibrate to distilled before you test.

 

[HuduVudu]

I just ordered one off eBay and it’s not giving a reading. So frustrating. I was so excited to get and use this as only read all but good things about it.

These are on sale all over the place for Black Friday. I saw one for $89. I used to pay that for refractometers, so for me that is a great deal.

 

[Randy Holmes-Farley Verified Community Expert]

I talked to milwaukee and they said rodi water will not provide correct results, must be distilled.

Secondly for those saying use a solution the button to calibrate is ZERO so how do you use a solution??

I've had zero problems with mine in 3 years. Always calibrate before using . It should also automatically adjust for temp.

I know this is old, but that is so nonsensical that I just had to correct it. No matter what they claimed, 0 ppm TDS RO/DI water is perfectly fine for calibrating a true seawater refractometer like this one.

It is also a fine idea to check them with a 35 ppt seawater standard, but I recognize that the Milwaukee cannot actually be calibrated using it.

 

[ckalupa]

 

[ckalupa]

New units come with the 0 solution and 1.026 check solution

 

[homer1475]

Regardless of how nonsensical it sounds(I actually agree with you), but I can tell you it does make a difference. When using RO/DI my milwaukee is always .002 then calibrating with steam distilled.

FWIW if you run out, email or call milwaukee. They will gladly ship you out a new bottle free of charge.

 

[Scorpius]

I've always used distilled water from the ol grocery store for the past six years. ¯\_(ツ)_/¯