Pool Temperature Sensor
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My pool temperature sensor has been working reliably for almost five years now, so I thought it was worth showing how I made it. It’s a DS18S20 on the end of a piece of cat-5 cable. The sensor is fed down a length of ¼” transparent plastic tube. This type of tube is used for wine-making, although I found it cheapest at my local boat shop. I formed a seal on one end by melting it inside a copper end-stop – the 15mm type used for plumbing. Hold the copper stop-end in a mole wrench and heat it gently on a gas hob, then gently feed the plastic tube into it. It takes a few minutes but the tube does eventually melt. When it’s done, cool it in cold water and saw the copper end-stop off. You have a totally water-tight end-stop that will never come off or leak:
Unfortunately you can only feed the cat-5 cable down about a metre of tube before friction prevents it going any further, but that was enough for me. I then sealed the cable into the tube with adhesive heat-shrink.
The sensor end sits in the skimmer. The tube turned white years ago, but it still works fine. |
