Review on 🌊 Ohaus ST10 Waterproof Pen Meter by Jimmy Hargrove

This meter cannot be calibrated. It becomes a useless piece of junk once the calibration fails. The piece of sponge that was supposed to be soaked in the storage solution was almost dry when I received it and the readings became inaccurate after only a few uses and since it couldn't be calibrated I was left with a piece of junk. I ordered Hana and sent it back. A Hana is significantly more expensive, but at least I don't expect it to become scrap after a few measurements. Note: This model does not measure ORP. The product description is generic to all Ohaus products (ie not specific to ST10) so be careful not to mislead you.