Review on ⛲ HM Digital 716160 Professional Waterproof by Byron Forman

I purchased my COM-100 meter over a year ago in February 2012 and it has worked flawlessly so far. I bought a bottle of 1000 ppm calibration solution with the meter. So far every test I've run on the meter's accuracy has been right for the money with no need to adjust the calibration and I'm still using the original batteries. I mainly use this meter to check the concentration of ionic colloidal silver, which I do at least once a month. I also use it to check the ppm in my home water, hot and cold, and purified water produced by my reverse osmosis machine. The RO machine takes my household water at 350ppm and purifies it to <20ppm. I can also tell when the reverse osmosis filters need to be replaced by watching the ppm slowly increase over time. Honestly, this little TDS meter has proven to be very valuable as it has allowed me to monitor and control the quality of the water and colloidal silver that I use. Recommended for anyone who wants to buy such a tool. For me it works GREAT. Update: February 1st, 2014 I continue to use this meter frequently to test TDS/ppm: tap water, reverse osmosis water, pool water, rainwater, roof water, steam distilled water and even colloidal water. Silver I welded. I also bought a 1000ppm TDS-HM test solution that I use sometimes to check accuracy. I never had to recalibrate it. This is a great testing tool that seems to be quite durable and very accurate. I've been using it for almost two years, the battery hasn't been changed yet. My recommendation is BUY.