Review on Vktech 10pcs 3M Waterproof Digital Temperature Temp Sensor Probe DS18b20: Reliable and Waterproof Temperature Sensor for Accurate Readings by Derek Dolla

I bought these about a year ago and used them connected to a Raspberry Pi single board computer to build a temp recorder. They worked great! Ten foot leads are very flexible and the metal sleeve provides good thermal conductivity to the surface being measured - I used aluminum tape for this purpose. I haven't tested if they're actually waterproof, but the heat shrink tubing fits snugly to the metal tips - so probably yes. I haven't tested the accuracy, but since it's basically a one-chip solution - temperature input to digital output - the chip manufacturer's specification probably applies. In the logger app, all sensors are wired in parallel to the GPIO pins on the Pi - super easy. In theory, you can connect a large number of sensors to a Raspberry Pi if the cable length is set correctly. I had no problem reading 10 sensors with a Pi. For more information on creating a logger, including Python code, see the Instructibles website. Just search for "Raspberry Pi Temperature Recorder DS18B20".