How to properly use milwaukee digital refractometer

[skiergd011013]

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.

 

[Randy Holmes-Farley]

Suppose that the specific gravity is 1.0255. You'd expect the reading to vary between 1.025 and 1.026.

 

[USMC 4 LIFE]

I’m contemplating on buying one. If I️ understood you correctly, this expensive refractometer doesn’t read tenths of a unit?

 

[skiergd011013]

Suppose that the specific gravity is 1.0255. You'd expect the reading to vary between 1.025 and 1.026.

very well could be. I just wanted to keep my tank at 1.025 because i top it off manually morning and night. I figured as it evaps, it would only rise to .026 or so. Either way, its probably no big deal.

 

[skiergd011013]

I’m contemplating on buying one. If I️ understood you correctly, this expensive refractometer doesn’t read tenths of a unit?

it reads to the thousandths. So goes beyond that.

 

[WWIII]

I’m contemplating on buying one. If I️ understood you correctly, this expensive refractometer doesn’t read tenths of a unit?

It reads in the thousandths. If it didn't it wouldn't be much help. Consistency is more important in this case and +/- .001 isn't going to make much difference imo.

 

[Randy Holmes-Farley]

Despite calibrating it with pure fresh water (in this case you must), it is still worth checking these with a standard 35 ppt solution to be confident in the answer.

Some folks have had issues with it, but I'm not sure why.

 

[atticus]

I was having some issues with mine and had a lengthy convo with man guy with tech support. To make sure that your unit is spot on accurate you need to be sure it is starting at true zero – ( zero is 1.000 SG )

First clean the base lens with Windex using a heavy Windex soaked Q-Tip or cotton ball – Then flush the Windex out of the pan by using the pipette we provide using “Steam Distilled Water” & do 2 or 3 loads of the pan and dump out or extract the distilled water using the pipette [ you MUST use “Steam Distilled Water” ] and then -- load the pan ½ way with “steam distilled water” ( you can’t use RO or DI water for this unit ) and press “zero” by doing this you are sure no residual salt or refraction material is on the lens– Another note: Your solution should always have a pan volume that is 1/3 to ½ full of distilled water for the zero and also that much of the tested sample. In addition, never double test the same sample – if you want to do a retest dump the first sample, flush the pan or blot out leftover first sample liquid and go back to the original source and get another sample. This is to prevent sedimentation of the sample that will give a distorted reading on the second reading.

To validate accuracy you should be using Seawater validation solution that is provided with your unit. @ ( 1.025 SG ) – Never use conductivity calibration solution. The reason is that Conductivity probes, like the Neptune and Pinpoint, are designed for NaCl testing and not Seawater. Most "validation" liquids for refractometers are made from Sodium Chloride [NaCl ] @ 99% - one of the providers of this on the internet is Sybon Scientific and there are others. The problem with their solution is that it is designed for Salinity validation not for Seawater. Their solution is Sodium Chloride [NaCl ] @ 99% and seawater is made up of Sodium Chloride [ NaCl ] @ 97% and Potassium Chloride [ KCl ] @ 2% and Other Trace Minerals Salts @ 1% and that 3% makes a huge difference.

Using this popular salinity liquid sellers, Sybon's, own chart http://www.premiumaquatics.com/prodimages/tropiceden/Sybon_refracto_cal_solution.jpg you will see that their solution is rated at 35ppt of Sodium Chloride and has a SG of 1.0264 SG and 53 mS/cm @ 77F which is their target for their salinity measurement units but that is for "Salinity Meters, Testers & Refractometers" not Seawater and their primary target is PPT/PSU or mS/cm. However, the optimum target for a seawater aquarium is 1.0250 sg @ between 68° F to 72° F (20/20). -- this brings up a point that all of this should be done at 70 F not 77 F.

The only way to validate your unit is with an independent actual seawater validation solution kit however if you are at +/- 0.001 SG you are within the units’ accuracy specification.

 

[skiergd011013]

I was having some issues with mine and had a lengthy convo with man guy with tech support. To make sure that your unit is spot on accurate you need to be sure it is starting at true zero – ( zero is 1.000 SG )

First clean the base lens with Windex using a heavy Windex soaked Q-Tip or cotton ball – Then flush the Windex out of the pan by using the pipette we provide using “Steam Distilled Water” & do 2 or 3 loads of the pan and dump out or extract the distilled water using the pipette [ you MUST use “Steam Distilled Water” ] and then -- load the pan ½ way with “steam distilled water” ( you can’t use RO or DI water for this unit ) and press “zero” by doing this you are sure no residual salt or refraction material is on the lens– Another note: Your solution should always have a pan volume that is 1/3 to ½ full of distilled water for the zero and also that much of the tested sample. In addition, never double test the same sample – if you want to do a retest dump the first sample, flush the pan or blot out leftover first sample liquid and go back to the original source and get another sample. This is to prevent sedimentation of the sample that will give a distorted reading on the second reading.

To validate accuracy you should be using Seawater validation solution that is provided with your unit. @ ( 1.025 SG ) – Never use conductivity calibration solution. The reason is that Conductivity probes, like the Neptune and Pinpoint, are designed for NaCl testing and not Seawater. Most "validation" liquids for refractometers are made from Sodium Chloride [NaCl ] @ 99% - one of the providers of this on the internet is Sybon Scientific and there are others. The problem with their solution is that it is designed for Salinity validation not for Seawater. Their solution is Sodium Chloride [NaCl ] @ 99% and seawater is made up of Sodium Chloride [ NaCl ] @ 97% and Potassium Chloride [ KCl ] @ 2% and Other Trace Minerals Salts @ 1% and that 3% makes a huge difference.

Using this popular salinity liquid sellers, Sybon's, own chart http://www.premiumaquatics.com/prodimages/tropiceden/Sybon_refracto_cal_solution.jpg you will see that their solution is rated at 35ppt of Sodium Chloride and has a SG of 1.0264 SG and 53 mS/cm @ 77F which is their target for their salinity measurement units but that is for "Salinity Meters, Testers & Refractometers" not Seawater and their primary target is PPT/PSU or mS/cm. However, the optimum target for a seawater aquarium is 1.0250 sg @ between 68° F to 72° F (20/20). -- this brings up a point that all of this should be done at 70 F not 77 F.

The only way to validate your unit is with an independent actual seawater validation solution kit however if you are at +/- 0.001 SG you are within the units’ accuracy specification.

thanks for the response. Im just going to follow my instructions. I will not use windex on AQ equipment. My pippet touches this unit, and i flush the prism reservoir with water to be tested before using, to hopefully gain accuracy. I dont want any trace of windex in my tank. To clean the prism of salt residue, i let the tap run over it, then paper towel it dry. Also, right in the manual, it says you can use deionized water to calibrate. So the service tech is directly contradicting the instruction manual. Ugh!

 

[atticus]

thanks for the response. Im just going to follow my instructions. I will not use windex on AQ equipment. My pippet touches this unit, and i flush the prism reservoir with water to be tested before using, to hopefully gain accuracy. I dont want any trace of windex in my tank. To clean the prism of salt residue, i let the tap run over it, then paper towel it dry. Also, right in the manual, it says you can use deionized water to calibrate. So the service tech is directly contradicting the instruction manual. Ugh!

Any glass cleaner can be used. And rodi water should not be used. I use these instructions and mine has been dead on every time.

 

[skiergd011013]

Any glass cleaner can be used. And rodi water should not be used. I use these instructions and mine has been dead on every time.

thanks for all your help. Its still bugging me. Ive been reading threads and many people complained about the same thing. I have a tried and true sybon refractometer as well that i trust. I just ordered some 35 ppt calibration fluid for it. Im going to calibrate the sybon and use it to check against the milwaukee. My tank looks great, great polyp extension etc. But i want a salinity measurement that i trust.

 

[Velcro]

My method to properly using mine was selling it and buying a conductivity meter. The Milwaukee costs way too much to have such poor accuracy.

 

[roberthu526]

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.

 

[vertigo01]

I recently purchased one and have to say that in comparing it's results with that of the LFS I trust, it is dead on.

 

[skiergd011013]

Ill see how dead on mine is once my calibration fluid comes on tues.

 

[Randy Holmes-Farley]

( you can’t use RO or DI water for this unit ) .

They may have said that, but it simply isn't true. RO/DI with anything close to 0 ppm TDS is perfectly adequate. I can prove this mathematically, if you insist.

I

To validate accuracy you should be using Seawater validation solution that is provided with your unit. @ ( 1.025 SG ) – Never use conductivity calibration solution. The reason is that Conductivity probes, like the Neptune and Pinpoint, are designed for NaCl testing and not Seawater. Most "validation" liquids for refractometers are made from Sodium Chloride [NaCl ] @ 99% - one of the providers of this on the internet is Sybon Scientific and there are others. The problem with their solution is that it is designed for Salinity validation not for Seawater. Their solution is Sodium Chloride [NaCl ] @ 99% and seawater is made up of Sodium Chloride [ NaCl ] @ 97% and Potassium Chloride [ KCl ] @ 2% and Other Trace Minerals Salts @ 1% and that 3% makes a huge difference.

Using this popular salinity liquid sellers, Sybon's, own chart http://www.premiumaquatics.com/prodimages/tropiceden/Sybon_refracto_cal_solution.jpg you will see that their solution is rated at 35ppt of Sodium Chloride and has a SG of 1.0264 SG and 53 mS/cm @ 77F which is their target for their salinity measurement units but that is for "Salinity Meters, Testers & Refractometers" not Seawater and their primary target is PPT/PSU or mS/cm. However, the optimum target for a seawater aquarium is 1.0250 sg @ between 68° F to 72° F (20/20). -- this brings up a point that all of this should be done at 70 F not 77 F.

The only way to validate your unit is with an independent actual seawater validation solution kit however if you are at +/- 0.001 SG you are within the units’ accuracy specification.

That too is simply incorrect.

The Pinpoint is a 35 seawater mimic and is suitable for refractometers. It is not just sodium chloride.

MY DIY for a refractometer is pure sodium chloride with refractive index of 35 ppt seawater. It is not 35 ppt sodium chloride, which would be inappropriate.

Both work perfectly for testing a seawater refractometer (when made correctly)

 

[Randy Holmes-Farley]

And rodi water should not be used. I use these instructions and mine has been dead on every time.

Nonsense.

 

[atticus]

Nonsense.

Don’t take this the wrong way because text has no emotion so not being an butt. I’m no scientist or chemist just stating what I was told from the head guy there. I’m still new to the hobby and had issues with mine reached out to BRS and they sent me to Milwaukee. Talk to the guy for about 30 min. and stated explaining stuff to me that was outta my league so took in as much as I could. He was stating that no matter what rodi unit I had that nothing is better than steamed distilled water. And went on to explain how both refactors work and as he stated that all refactors should always be calibrated to 0 and not to specific point.

 

[Velcro]

Don’t take this the wrong way because text has no emotion so not being an ***. I’m no scientist or chemist just stating what I was told from the head guy there. I’m still new to the hobby and had issues with mine reached out to BRS and they sent me to Milwaukee. Talk to the guy for about 30 min. and stated explaining stuff to me that was outta my league so took in as much as I could. He was stating that no matter what rodi unit I had that nothing is better than steamed distilled water. And went on to explain how both refactors work and as he stated that all refactors should always be calibrated to 0 and not to specific point.

All refractometers should be calibrated to zero? Hahahaha. Don’t know how he got that job.

 

[skiergd011013]

Nonsense.

do you recommend i use s.g, or ppt?