The following product is basically a 2m long wire temperature sensor. What’s great about it is that it’s waterproof, as well as the fact that it’s suitable for detecting temperature that is immersive. There’s a chip inside of it (DS18B20).
Check out the different resources contained on the internet about it! It can be used as a regular grove sensor since we have made some adjustments to it. Note that the original one includes 3 wires and an extra resistance in order for it to work; we have made some changes regarding it.