Which one is more accurate?

[sdelli]

I have two testers First one is a Hanna P5 and the other is a Vinmetrica SC-300 .... I test the Ph level in some wine. The p5 says 3.16 and the SC-300 says 3.33... Calibrated both two times and there is always a .10 to .20 difference between the two! Sc-300 always higher.... Only difference is the SC-300 is kept in a storage bottle of liquid and the PH5 just with the cap on... So..... Which one is more accurate? Which one do I believe? Sucks to have two units so now they can conflict!

 

[Runningwolf]

Your not the first to complain about this. I just tested some wine for another winemaker that was using the phep 5 and another expensive meter. I would put my faith in the vinmetrica over the phep 5.

 

[Chiumanfu]

If the Hanna was stored dry then it is the one that is out of whack. If a pH sensor is allowed to dry out it does not last very long. you can rehydrate it with pH4 solution and hope it regains accuracy.

Always keep your pH sensor in pH4 or special storage solution.

http://www.hannainst.com/usa/whitepaper/CareandstorageofpHelectroderev4.pdf

 

[sdelli]

Thanks! I knew it was better to store wet but did not realize you can just fill the cap on the sensor to do this... I know... Simple but sometimes the simple is overlooked. Do I need to purchase storage solution or can I use the ph 4 calibrate solution for storage?

 

[Runningwolf]

Use the ph4. Usually when you purchase the phep5 it has a tiny sponge in the cap to hold the moisture you pour in it.