A pH meter is a digital electronic device that can be used to measure the pH of our formulations. An electric/digital pH meter is significantly more accurate than pH strips, so if you’re interested in working with pH-sensitive ingredients (some actives, most natural preservatives) I highly recommend investing in a pH meter over pH strips. Strips are generally fine for determining if something is acidic or basic, but if you are working with a preservative that needs to be used below 5.5 or some other precise number, you’ll want to use a meter.
The pH meter I have is made by Apera, model number AI311 (USA / Canada). It is accurate to 0.01pH with a range of -2 to 16, which more than covers the pH range I work within. It came with calibration and storage fluid (a 3M KCL solution), though I have had to purchase more of the storage solution (USA / Canada) since purchasing the meter. I purchased this pH meter back in 2017 and I’ve been happy with it.
When measuring the pH of your formulations you’ll want to create a 10% dilution and test that; learn more about why here.
I’ve made a video on how to test and adjust pH using this pH meter; it’s a patron-exclusive for $10 and up patrons.