Ma877 calibration?

[Notsolostfish]

The “recipe” is to make 35ppt solution which is 1.0264. So 1.026 or 1.027 are exactly what you would want to see and easily within the accuracy of the MA887. What specific gravity were you expecting? Also you can change the readout on the Milwaukee to ppt and see what it gives.

Oh wait i thought i need dead on 1.026

 

[Gtinnel]

Oh wait i thought i need dead on 1.026

No the actual value will fall between 1.026 and 1.027 so either is good, and even off by .001 is fine.
Most of our hobby grade test equipment aren’t that accurate, which is why stability is way more important than accuracy with salinity. The Milwaukee MA887 only has a stated accuracy of 2ppt.
It sounds to me that your Milwaukee is calibrated and working properly.

 

[Notsolostfish]

No the actual value will fall between 1.026 and 1.027 so either is good, and even off by .001 is fine.
Most of our hobby grade test equipment aren’t that accurate, which is why stability is way more important than accuracy with salinity. The Milwaukee MA887 only has a stated accuracy of 2ppt.
It sounds to me that your Milwaukee is calibrated and working properly.

So basically now when i mix my salt for my tank do i aim to 1.026 on the device? Or if i want 1.025 i need to 1.027?

 

[Gtinnel]

So basically now when i mix my salt for my tank do i aim to 1.026 on the device? Or if i want 1.025 i need to 1.027?

When you make water for your tank you shouldn’t need to adjust your reading. If you want your water to be 1.025 just make it to where the Milwaukee reads the new tank water at 1.025. It may not be exactly 1.025 but it will be a close as you’ll likely get with hobby grade equipment.

 

[Randy Holmes-Farley Verified Community Expert]

I'm not sure I understand the lingering confusion.

Let's make the solution, calibrate the refractometer with fresh water, measure the standard, see what it reads, and then we will advise what to do about it if it is not close enough to sg = 1.0264.

If it is close enough that you do not care about the difference, then you need to do nothing more except use the device on your tank water.

 

[Notsolostfish]

I'm not sure I understand the lingering confusion.

Let's make the solution, calibrate the refractometer with fresh water, measure the standard, see what it reads, and then we will advise what to do about it if it is not close enough to sg = 1.0264.

If it is close enough that you do not care about the difference, then you need to do nothing more except use the device on your tank water.

The confusion is. I did the solution. And i tested i got first 1.026 minute later i got 1.027. And then i got 1.028. I made a new batch of water with salt. And i got 1.027. But thats probably because my kitchen scale cant see after the decimal. So if im getting 73.6g i cant see that. All i see is 73g on my scale. But yes i got 1.027 as the latest batch i got not 1.026

 

[Randy Holmes-Farley Verified Community Expert]

The confusion is. I did the solution. And i tested i got first 1.026 minute later i got 1.027. And then i got 1.028. I made a new batch of water with salt. And i got 1.027. But thats probably because my kitchen scale cant see after the decimal. So if im getting 73.6g i cant see that. All i see is 73g on my scale. But yes i got 1.027 as the latest batch i got not 1.026

That all seems fine and is well within specifications for this device (which only claims +/- 2 ppt).

Just use the device on tank water. If it reads a bit high or a bit low is no concern since salinity need to be highly precise.

 

[Notsolostfish]

That all seems fine and is well within specifications for this device (which only claims +/- 2 ppt).

Just use the device on tank water. If it reads a bit high or a bit low is no concern since salinity need to be highly precise.

So basically if it want 1.025. Its not reallt 1.025 it can be 1.023

 

[Randy Holmes-Farley Verified Community Expert]

So basically if it want 1.025. Its not reallt 1.025 it can be 1.023

If you want a sg of 1.025, you should target 1.025 on your refractometer. It will be fairly close.

if you had not checked it with a standard, that reading of 1.025 might come from water that was anywhere between 1.023 and 1.027, and still be consistent with the manufacturer specifications.

Your particular unit may be more accurate than that since the standard was pretty close.

 

[Notsolostfish]

If you want a sg of 1.025, you should target 1.025 on your refractometer. It will be fairly close.

if you had not checked it with a standard, that reading of 1.025 might come from water that was anywhere between 1.023 and 1.027, and still be consistent with the manufacturer specifications.

Your particular unit may be more accurate than that since the standard was pretty close.

So basically as long as i used the solution i made yesterday. The solution i made yesterday showing me 1.027. So im still basically within range

 

[Randy Holmes-Farley Verified Community Expert]

So basically as long as i used the solution i made yesterday. The solution i made yesterday showing me 1.027. So im still basically within range

Yes, and that solution will last a very long time.