Review on Apera Instruments SX620 pH Pen Tester Kit: Accurate Results with 0.01 pH Accuracy, 3-Point Auto Calibration, and ATC by Richard Alemayehu

I have lab results to compare to the accuracy of this pH pen and let me tell you it's still a long way to go. It's easy and quick to calibrate, and that's the only thing it has. I test a soil suspension sample for ph, it always shows the same value no matter where the sample is taken. Lab results say 7.6, this pH meter says 9.4. Please, my tomatoes disagree. I test with distilled water, 6.3. No, it is actually 7.0. Then I decide to backfill with peat mud pH 3.9. The counter shows 5.3. So if it's calibrated, it's as accurate as can be, do a test, rinse with distilled water, then check the buffer again, and the calibration will be off by half a point after just one test. I calibrated it before bed, then stored as instructed, buffered in the morning and the calibration was off at 0.2ph. I won't even mention the slow response time. This is being returned for a refund as I contacted the manufacturer on their website and opened a support ticket. Well no reply from them so back to Revain so they can throw it away.