I have purchased 2 of those cheap VIVOSUN pH checker pens....and have had both of them quit working so I am done with them. I am looking to purchase a Hanna pH checker. However....there are a couple of different models. There is a pen style checker that looks like it has been around longer and there is also the Hanna color reagent pH checker that looks similar to all of Hanna's other color reagent checkers.
The red one is the Hanna Instruments HI98103
The grey one is the Hanna Instruments HI780
I would rather have something that is quick read but I realize that both of them will require calibration. Which one do you think is best??
Here they are side by side:
The red one is the Hanna Instruments HI98103
The grey one is the Hanna Instruments HI780
I would rather have something that is quick read but I realize that both of them will require calibration. Which one do you think is best??
Here they are side by side: