Best salinity tester???

[Randy Holmes-Farley Verified Community Expert]

The only one that never needs to be calibrated….tropic Marin high precision hydrometer.

That isn’t true (my conductivity meter could not be calibrated), but the TM hydrometer is a fine device if you validate its accuracy at least once and make proper temperature corrections.

 

[Randy Holmes-Farley Verified Community Expert]

, a refractometer with ATC is generally calibrated at 20c, so if you need to alter your refractometer you should really adjust it only when the device is at the calibrated temp of 20c, the ATC is not used for calibration.

I understand they make that claim, but I have never understood how it could possibly be true, and I don’t think it is.

The correction for temperature is a purely mechanical movement of a temperature sensitive piece of metal, and it is never turned off (cannot be) in a normal handheld refractometer. Thus, calibration at any temp within the ATC range will be autocorrected just like a measurement would be.

 

[Mechano]

That isn’t true (my conductivity meter could not be calibrated), but the TM hydrometer is a fine device if you validate its accuracy at least once and make proper temperature corrections.

Ah yes. A conductivity meter. Doubt many people use them but true.

And yes on the TM hydrometer! I tested vs 2 other hydrometers and a refractometer and one of those cheap float style hydrometer to make sure the calibration was correct. Then just keep it clean and good to go.

 

[Mechano]

I do have a glass sera one not big like the TM. Doesn’t the temperature have to be 77f for the readings to be correct?

Yes. I also have that sera one actually and it’s pretty decent, but honestly the TM one is better quality and worth it.

 

[Reef.]

That isn’t true (my conductivity meter could not be calibrated), but the TM hydrometer is a fine device if you validate its accuracy at least once and make proper temperature corrections.

“Could not be calibrated” is not the same as “needs calibration” just because it can’t be calibrated doesn't mean it didn’t need calibration.

 

[Randy Holmes-Farley Verified Community Expert]

“Could not be calibrated” is not the same as “needs calibration” just because it can’t be calibrated doesn't mean it didn’t need calibration.

Perhaps. Neither the TM hydrometer nor my Orion 128 conductivity meter can be “calibrated” in the sense of anything automatic or adjusted on it. Both can be manually determined for accuracy and an offset determined, if needed.

My Orion never varied in its response to a standard in the many years I used it. It always read the same tiny bit low and I always took that into account. So it never needed any ongoing adjustment, and I think it is fair to say that it never needed any adjustment/calibration.

 

[Leon821019218]

Been using the Milwaukee digital refractometer for over a year now. Was not the cheapest option but after 2(!) different refractometers steered me wrong and got me into a lot of trouble, I'm glad I bought it. Works perfect and my salinity is on point.