Review on American Marine PINPOINT Monitor Calibration by Emily Mason

Not worth the money. Once calibrated, this pH monitor works well enough for the next use, but spot accuracy (within manufacturer specifications) requires calibration before each use. I think this pH monitor is best suited for use in an aquarium, pool, hydroponics or any situation where you need to constantly monitor the pH without removing the probe from the liquid. It doesn't work as well as an instrument used to measure the pH of different liquids by dipping the probe into each liquid, as it seems to need to be calibrated each time it's used with a different liquid. To be honest, in most cases it's better to use litmus paper strips or a chemistry test. *Update: For a while the device worked reasonably well and gave stable readings when calibrated before each use, but after almost six months of use it started giving erroneous readings. Indications and intentionally wrong results, and even calibration did not help. For example, even when properly calibrated, there were three different readings for a sample of white vinegar (pH 2.3) with readings ranging from 1 to 14. Sometimes the readings fluctuate so much that it is impossible to even determine a vinegar pH -Get value. a gallon of tap water (for my location, the pH ranges from 7.5 to 8.5). According to this device, the plumbing company sometimes pumps hydrochloric acid out of my faucet! However, it is sometimes very accurate when tested against a known pH or other pH measurement method. I suspect the device itself works fine, but the probe is fragile and unstable and needs to be replaced. I bought a replacement sensor (2/1/15) and will see how it works. I will update this review after calibrating and testing this new sensor for a while.