Review on Waterproof Ultrasonic Sensor JSN-SR04T For Arduino: Integrated Distance Measuring Transducer With Improved SEO by Patrick Biletnikoff

I bought two of these and one worked and the other did not. During Summer I was very happy with the working one for our 2500 water tank. It occasionally sent a crazy figure but the level did not change much each day so I ignored anything over the tank depth and averaged the rest. All good enough.Then came Fall and the temp dipped to 18-F-degrees. We have pipe-tape heaters on the tank pipes to prevent freezing so not a big deal. But, the JSN board just gave up and sent weird numbers all the time until the temp came up to around mid 30-F during the afternoon.So, I am now concerned for Winter as clearly these things do not have a very wide operational temperature range.I will have to look for a better alternative and thow this one in the trash. If you live in a year-round warmer climate these may be good enough. But if the temps fall below about 20-F they are no use at all.