## Re: [mh] Measure water temp

 Re: [mh] Measure water temp From: Jim Serack - 2006-09-29 02:39:05 Attachments: Message as HTML ```Tim, =20 I have made a number of water proof temperature sensors using DS18S20 = 1-wire sensors. They use a TO-92 case (looks like a transistor). I have used two approaches depending on the pressure, either I form PVC plastic around the sensor (like clear 1/4 water line for the icemaker) = which has the advantage of fitting in plumbing fittings so that it can be = inserted into a pressurized system, or I use heat shrink tubing for atmospheric pressure - which would be what you need for an aquarium.=20 =20 Here is what I did for my pool. (I had several leaks before finding this method; U tube both ends above maximum water level, double layer to = avoid leakage.) =20 1) Get a suitable length of cat 5 cable. 2) Get four diameters of heat shrink tubing a) 36 or 48 inches of 3/16 (for a depth of 17 inches, or 23 inches = into the water b) 36 or 48 inches of 1/4=20 c) 3 inches of 1/16 (cut into 3 one inch sections) b) 2 inches of 1/2 tube. 3) strip back the cat 5 cable removing all but the three wires you are = going to us for the 15 inches (21 inches) 4) Place the 3 heat shrink sections over the ends of the wires and move = them up away from the solder joints 5) Solder the wires to the DS18S20 - make sure you use the "pair" for = data and return and the odd wire for power. 5a) optional - add additional DS18S20s along the wires at intervals with insulators=20 (For example I have 4 sensors in about 8 inches, two within an inch = of the target water level for the pool, one 8 inches into the pool, and one above the maximum level of the pool water, with this I can measure pool depth, pool temperature. 6) Slide the 3/16 tube inside the 1/4 tube (e.g. double glove) 7) Slide the wire with the sensors into the tubes - upto half way and = far enough that the tube overlaps the CAT5 jacket by about 2 inches 8) Heat shrink the tubes onto the sensor 9) Now fold the tube in two so that the sensor is at the bottom and the = tops of the U are both together (although one has a Cat5 cable coming out of = it) 10) Slide the 1/2 section over the bottom of the U and up to the tops of = the U, fold the empty top back onto itself and cover with the 1/2 tube and = apply heat to shrink. 11) Put appropriate connectors on the other end of the able and try it = out. =20 Jim =20 -----Original Message----- From: misterhouse-users-bounces@... [mailto:misterhouse-users-bounces@...] On Behalf Of = TimC Sent: September 26, 2006 7:49 PM To: misterhouse-users@... Subject: [mh] Measure water temp I'd like to build an interface to read the water temperature in an = aquarium. I do have experience with the 1-wire sensors, but only the button style = temp devices which are obviously not water tight. Any pointers would be appreciated. Thanks! T. ```