Milwaukee Digital Refractometer

[Marchillo]

So my ATC broke and opened the wallet for this. So I calibrate it and then test my tank. 1.028 then again 1.030 then again 1.030 and then finally 1.026 where I believe it should be.

I clear out whatever pippette I'm using by filling squeezing out. I guess salt creep could get on the end when navigating through eggcrate. Would SG be higher at the surface? Do I need to put it in deeper? Anyone else experience this?

Basically what is best practice to put water on the prism for accurate results

Thanks - Steve

 

[Marchillo]

Or is this just not a very good refractometer? I read good reviews.

 

[bitwise]

I use one pipette to get a small amount of water (suck water in and push out a couple times to flush it), you only need a bit of water. With the unit already turned on, put the sample in and hit the button.

Afterwards, absorb the water in the cavity with something like a piece of toilet paper. Then take another pipette and put a few drops of ro water in the cavity, and then wipe it clean being sure to really get the glass clean.

You should also flush out the salt water pipette from time to time with ro water.

That's my process, good luck.

 

[mitchrapp]

I never got good results with it. It was always .02 off from a calibrated solution which my analog refractometer always measured spot on. I returned it.

 

[Marchillo]

When I tested my new water going in it tested 1.026 3 x's in a row. Maybe some user error when putting the pipette into the tank, but not convinced. I'll keep trying unfortunately .01-.02 off isn't good in this case.

 

[theatrus]

I have to be more diligent in zeroing it out but I've had great results in general.

 

[hart24601]

I don't like mine. Now it just sits on the shelf. It was always off from the standard solution, it did give very consistent results, just always low. Considering how easy my cheap refractometer is to use and that it matches 2 standard solutions I don't see a reason to use the digital one. Not my greatest purchase. Why use the digital if the cheap regular refactometer is faster and spot on?

 

[reefwiser]

I learned how to use a digital meter at work. [emoji3] As we use digital everywhere. Never had a problem with the Milwaukee.

 

[Marchillo]

My refractometer developed a crack inside somehow and a free one I got is blurry to me. Figured this was the way to go. I hated having to be right under a bright bulb to pick up the color. Anyways I'll give this a shot for a while.

 

[SFish]

So my ATC broke and opened the wallet for this. So I calibrate it and then test my tank. 1.028 then again 1.030 then again 1.030 and then finally 1.026 where I believe it should be.

I clear out whatever pippette I'm using by filling squeezing out. I guess salt creep could get on the end when navigating through eggcrate. Would SG be higher at the surface? Do I need to put it in deeper? Anyone else experience this?

Basically what is best practice to put water on the prism for accurate results

Thanks - Steve

Not sure what the complaint is this is a tight grouping. Says the accuracy is
+/- 0.002 of the instrument.

 

[Marchillo]

Not sure what the complaint is this is a tight grouping. Says the accuracy is
+/- 0.002 of the instrument.

By my count 1.026 and 1.030 is off by .004. If the tank was 1.028 then this would be true. But my strong belief is 1.026. Like I said I'm gonna keep using it. Just hope I had salt on the end of the pippette or something. Lol

 

[dbl]

I've been using one for nearly a year. I've only had to calibrate it once upon checking it. It's proven to be very accurate test over test. Maybe I'm just lucky!!!

 

[Pigpen17]

I just recently started having problems with mine. It's always high + .01 by the calibration fluid. I guess this is within tolerance, but it bugs me anyway. It used to be spot on. Now I always double check between my refractometer and my hydometers.

I have had wild readings for a second, but I clean it and start over and then it's back. The only tip I have been told is to let the tank water sit for a few seconds on the glass to become the temperature of the unit. I don't feel this has changed anything though.

If I had to re buy at some point, I may try another brand.

 

[SFish]

By my count 1.026 and 1.030 is off by .004. If the tank was 1.028 then this would be true. But my strong belief is 1.026. Like I said I'm gonna keep using it. Just hope I had salt on the end of the pippette or something. Lol

1.0285 is the mean so your with in range. You don't know the true number. The nubers don't have to be with in 0.02 of each other. Also is it with in +/-0.002 of your standard?

 

[CHSUB]

just keep testing till you get the "right" reading.

 

[snorvich]

I prefer analog. However any test equipment will have a standard error of the mean and many suppliers provide that information.

 

[SFish]

His standard deviation is 0.001658

Accuracy has to do with how far off you are from your standard which means you should be +/-0.002 from it. Precision is how far off your readings are from each other so they can be further then +/-0.002 from each other. Nothing is error free. Not even a hand held refractometer.

 

[Marchillo]

I really started this thread to see how others fared and not get into a statistical argument. If the sg is 1.026 and I'm getting 1.030 that is a problem. I think something must have happened so I'm equating that to human error. I am getting readings of 1.026 consistently now. I've got a back up analog and a hydrometer so if if kept registering way off from my belief Id cross check it. Heck I'll probably do that regardless.

Thanks all for the replies. I'll be more careful when using it.

 

[Deinonych]

How are you calibrating it? Milwaukee recommends zeroing it with distilled water (RO/DI works too). I've been very pleased with mine.

 

[Marchillo]

Yeah that's what I did. I think I said it but I am putting the pippette through my eggcrate and I went from 1.028 to 1.03 twice then back to 1.026. Guessing I got an extra spec of salt or something. Readings seem better now.