Review on 🌊 Extech EC400: Waterproof Conductivity & Temperature Meter for Accurate Measurements by Richard Simmons

I purchased this Extech EC400 Conductivity, Total Dissolved Solids, Salinity and Temperature Meter to check the salinity in our pool. We have a salt water pool and a built in chlorinator and the salinity is important for the chlorinator to work. For this application you would typically use the salinity function which is displayed in ppm (parts per million) NaCl (salt) or ppt (parts per thousand). My pool system recommends a salinity of 2800-3200 ppm. Extech reads these values in ppt, which is 2.8-3.2 ppt. This device is not a toy. When I first received it, I took it to the lab to compare it to the tools and standards available there. I first tried the 500ppm NaCl standard and the EC400 showed 501 which is excellent. I then compared the readings from several different bodies of water using the EC400 and our expensive lab instruments and again found great agreement between the EC400 and the other instrument. This device is feature rich and can be a little intimidating. The screen is a little small for my eyes, but other than that it's a great purchase. To keep the sensors clean so they stay calibrated, be sure to rinse them with purified water (distilled water is good). Getting into really nasty water, oil, acid or alkali is likely to cause the device to malfunction. I haven't had it for a long time, but I'm very happy with what I see at first glance. I also plan to use this probe to test purified water I buy from the store to drink or brew. My pool water contains about 3.0 ppm salt or 3000 ppm. My tap water at home contains about 300 parts per million salt and purified water contains about 10 parts per million. The ultrapure water in my lab contains less than 1 ppm salt. You also need to understand that real water is a mixture of several different ions that combine to form salts, including sodium, magnesium, calcium, chlorides, sulfates, phosphates, and carbonates. to name a few. Most salinity meters, including this one, will read the salt concentration as if it were just NaCl and that's the reported concentration. This can be misleading if the water you are measuring contains many other salts and the concentration does not accurately measure the true salt concentration. It's better to live with chemistry.