Review on 🌡️ Hanna Instruments Combination Temperature Tester: Your Ultimate Solution for Accurate Temperature Measurements by Deejay Devarashetty

I bought a Hanna HI 98121 gauge to test the water in the pool. I had never used a pH/ORP meter before and didn't know what to expect. It took a lot of effort to get it working, but in the end it works fine and I'm happy with it. As others have noted, the storage solution that came with the hat has dried up. I couldn't get the pH to stay in calibration and the ORP function gave erroneous results. So I exchanged it for another of the same model. The replacement meter had the exact same problems. The instructions say to soak it in HI 70300 Storage Solution for one hour when the pH electrode is dry. However, I had to soak it for 4 days before the pH stayed in the calibration. The ORP function was still somewhat erratic, decreasing sharply when the solution was stirred and taking a full 90 minutes to settle down to a stable value. The manual recommends soaking in HI 7061 cleaning solution to clean the electrodes, but that didn't help. Hanna also recommends buffing the ORP electrode with jeweler's rouge, but that didn't help either. Some other manufacturers recommend polishing the platinum ORP electrode with baking soda. I gently buffed the platinum ORP electrode several times with baking soda on a damp cotton swab and it worked! The ORP function now provides stable readings after 2-4 minutes. (Don't polish the glass pH electrode.) Since both devices I tried arrived dry, I suspect the initial problems were due to old stock or improper storage rather than a manufacturing defect. I've read that pH electrodes have a finite lifespan, even if stored, so I'll try to find another source if I buy them again. Meter requires additional purchases of HI 70300 Storage Solution and HI 7061 Cleaning Solution and pH 4.01. and pH 7.01 calibration solutions for calibration and maintenance. This model has a replaceable pH electrode (part number HI 73127) but does not have the renewable reference junction found on some other Hanna models. didn't work as received and it took quite a bit of research and effort to get it working. Someone who is more familiar with this type of tool will likely encounter fewer problems. However, it now works well and provides simpler and more accurate readings than the standard pool test kit. UPDATE APRIL 12, 2016. As mentioned above, I was initially able to get this counter to work fairly well. However, he soon had problems again. The ORP readings got slower and slower, taking over an hour to stabilize. Cleaning the electrode did not help. Then the pH levels got slower and slower. I bought a replacement sensor ($53) directly from Hanna to (hopefully) avoid problems with old stock. However, the storage solution packaged with the new probe had long dried up and its performance was even worse than the original one. It takes about 1.5 hours to get a stable pH level in the pool water. After 2 years of frustration I found that the Hanna HI 98121 meter was an expensive instrument that never worked properly. Yellow pH meters sold for less than $20 work better. I will not buy it again nor recommend it. I am changing my rating from 4 to 2 stars.