Review on 🧪 Apera Instruments AI311 Premium pH Pocket Tester Kit: Waterproof, with Replaceable Probe for ±0.01 pH Accuracy by Allison White

I work in a lab and pH has always been critical when using meters that cost between $1500 and $4000. The main problems with gauges are accuracy and drift. Use case - We are raising freshwater shrimp, so our conditions are freshwater with a total dissolved solids content of 200-250 and pH is important for shrimp farming. Accuracy is the only real way to test the accuracy of calibration solutions - this little beauty was easy to calibrate and you check accuracy post calibration by switching from one test solution to another and looking for consistency (up to and including 7.00 and 4.00). Drift is how stable the reading is - we adjust the pH while the meter is in solution - if it drifts your reading is meaningless. This meter was very stable at constant pH and temperature. Tips: This is temperature compensated, but the temperature sensor is very slow - give it time to reach a steady temperature before trusting the pH. Do not attempt to read the pH for more than 20-30 minutes before placing the sensor back in the KCl storage solution for at least 20 minutes - this will protect the sensor and provide more stable readings (prolonged contact with the storage solution may damage the sensor) . ). All in all, it's a lot of money compared to a pen meter, but you might as well dip your finger in a solution and guess if it's acidic or alkaline than using a pen meter. So if pH is a factor I would buy this one - I've had it for 4 months. Take care of him and he will do his job.