My 25 year old NZ Hydroponics International nutrient tester started to get somewhat not reliable.
I purchased the Hanna Groline nutrient tester as replacement.
I'm still attempting to get used to the calibration of the Hanna tester.
I compare the readings of my OLD nutrient tester with my New Hanna tester. My hope is that I can find the new tester EC as compared with my old tester CF to be consistent. So far it feels like I'm getting some consistent readings. If my comparisons and my documentation work out, I think the Hanna tester will work out for me. The Truncheon type of testers have been my friend for over 25 years. I have never calibrated or maintained them other than washing after use and changing batteries about every 5 years or so.
