Making RTDS
Make the 20 foot long twisted wire
- 1 square tile in 550 = ~1foot
- Placing a piece of painters tape on one end of the room, place the end of the wire spool down to the ground, walk 20 tiles forward, placing another piece of tape to make 20 feet, and then cut the wire. Do this twice to get two 20 foot copper wires
- Tie a knot at one end of the wires.
- Place the large clamp that sits on the right side of the work table onto the floor where the first piece of tape is
- Place the knotted end of the two wires into this clamp and tighten it
- Holding both wires, walk to the other end of the room until the wires are taught and then make a loop in the wires ~1 inch long
- Grab the power drill from the red tool box.
- Place the loop of the wires into the drill’s mouth and tighten until they are held in place (CW = closes mouth, CCW = opens mouth)
- Plug in the drill once the wires are in place
- Holding the wire taught, making sure neither are sagging, press down on the drill to twist the wires and continue until the twists are roughly half a centimeter in length.
- Unplug the drill once you are satisfied
- Holding the wires in place so they do not tangle, slowly open the drills mouth and let the wires recoil in your hand. Then go and unclamp the other end.
- Wrap up the wire to keep it neat while you work with it for the following steps
Welding prep at the work table
- Grab the clear heat-shrinking tubes, the smaller black heat-shrinking tubes located either on the work table or in the bottom draw next to the probe station
- Cut off the end of the twisted wire with the knot, undo the first few twists, and then strip the tips of the copper to remove the insulation (use the 26 hole)
- Grab the RTDs from the temperature and humidity sensor draw near the sink (kept in a black/silver tinted bag)
- Cut a few millimeters off the end of the two rtd wires to make them easier to handle, and then place the white end of rtd into the right soldering clamp, making sure the wires stick out the bottom
- Cut two 1cm long black tubes and place them on the stripped ends of the copper wire
- Using the soldering clamps place one of the copper wires into the left clamp
- Line up the striped in of one copper wire to the left wire of the rtd, so that they are overlapping and touching.
Soldering
- Wet the sponge for the soldering machine
- Plug in the soldering machine and press the power button so that the solderer ramps up to 700.
- Before use, damp the end of the soldering pen on the sponge to clean it
- Melt some of the soldering wire onto the pen
- Place the soldering pen behind/touching the copper/rtd wire combo and melt the soldering wire (holding the silver soldering wire in front of the two wires) onto the two wires to bond them.
- Place the soldering pen back into the holder and turn off the soldering machine.
- Release the clamp from the twisted wire, and see if the bond is strong enough to hold it up. If so, move up the back tube to cover the bond
- Get the heat gun from the red tool cabinet, and use it to shrink the tubing over the bond.
- Repeat these steps for the second combo of rtd/copper wire
Once both ends of soldered and both back tubes are shrinked over the bonds, cut a 1 inch long piece of the clear tubing and place it over the bonded area
Use the heat gun to shrink this tubing
Testing the RTD
- Chop the loop end of the twisted wire off, and strip the ends of the wire
- Grab the yellow multimeter from 532, and set it to read resistance = 𝛀
- Touch both the black and red hook ends of the multimeter to either end of the twisted wire
- The RTD wires are platinum, which has a resistance of 100 ulms at 0°C, at room temperature it should be roughly 110 ulms
- If made correctly, the multimeter will read between 110-120 ulms.
- If it isn’t getting a reading, that means the bonds are not soldered properly. It is possible to use the soldering pen to reheat and melt apart the copper wire from the RTD, but there may not be enough platinum RTD wire left to rebond to. If so, you can cut off the end of the copper wire and start over.
- Once the RTD twisted wire is completed and tested, place the finished wire bundle on top of the right drybox in 550 for Nick to bring to the reactor (he usually needs at least 3 when he goes).