Hanna salinity tester readings differ from Tropic Marin's High Precision Hydrometer readings.

[Genvid]

My Hanna salinity meter, when checked, shows a measurement of 1.023. I checked with a Tropic Marin hydrometer, the reading was 1.025. then I calibrated the Hanna tester, with the calibration that was in the kit with the tester, but the readings remained the same, the expiration date of the calibration liquid was not indicated. Hanna tester has been reducing for almost two years now. What evidence should I trust? or buy a new sample of calibration fluid for Hanna tester.

 

[CoachRichardson]

They all have a margin of error. I have the Hanna also and am Disappointed with that margin. If you know it can be a point to two off and as long as it is holding stable I think you are fine. As long as it's nt getting to 27-28. Better to keep stable over time than to know and change an exact number.

 

[Genvid]

It's just that I always trusted Hanna tester, and now I have to always double-check.

 

[CoachRichardson]

It's just that I always trusted Hanna tester, and now I have to always double-check.

Yeah I think you will find they all have listed a margin of error on them somewhere. I know these are expensive but to get a more "exact" reading would cost a significant amount of money on equipment.

 

[Randy Holmes-Farley Verified Community Expert]

The Hanna claims +/- 0.001 sg. I’m not aware of any accuracy claims of the TM hydrometer, but two Hanna’s differing by 0.002 would still be within spec.

 

[MBruun]

When using a hydrometer / floater remember to use a salinity calculater like
https://reefapp.net/da/salinity-calculator
Then you are to have the correct salinity value since desity depend on the temperature

 

[KStatefan]

My Hanna always reads lower then my Tropic Marin hydrometer. It has averaged 0.00178 low in the six test I have taken this year. I checked the hydrometer when I first received to verify the reading by mixing the calibration solution from Randy's article.

 

[Genvid]

for no reason, my alk began to rise from 8.3 to 9.6, I think this is due to the fact that I read salinity incorrectly. I thought it was 1025 but it was 1027 -1028.