13 



model 275-618) 



(1) 680 ohm resistor 



(2) 20 cm length of 16 gauge stranded, single-conductor wire 



(1) PVC 'T' 



Instructions (refer to Figs. 14, 15) 



1. Drill a 3.0 mm hole in the top of the PVC T' (d, Fig. 15). 



a. Extend one of the resistor leads up through the hole and 

 solder to the anode of the LED (a, Fig. 14). 



b. Extend one end of a 20 cm length of 16 gauge wire up 

 through the hole and solder to the cathode of the LED (b, 

 Fig. 14). 



c. Lower the LED into the hole and cement into place. 



2. Drill a 13 mm hole on the side of the PVC T' (e. Fig. 15). 



a. Extend the second lead of the resistor through the hole 

 and solder to one of the contacts on the sensor indicator 

 switch (c, Fig. 14). 



b. Extend one end of the second length of 16 gauge wire out 

 through the hole and solder to the remaining contact on 

 the sensor indicator switch (d, Fig. 14). 



c. Insert the switch into the hole and cement into place. 



Assembling the Sensor PVC Housing 



Materials 



(2) 9 cm length of PVC tubing 



(1) length of PVC tubing (see below for length) 



Instructions (refer to Fig. 15) 



1. Saw two 9 cm lengths of PVC tubing. 



2. Assemble the two lengths of tubing, the two elbows, and the 

 PVC T'. 



3. Adjust the pieces so that the distance between the two 6.0 

 mm holes in the elbows is approximately 31 cm. 



4. Cement the pieces together with PVC cement. 



Preparing the Sensing Element 



Materials 



(1) spool of cotton chalk line 



(2) solderless ring tongue lug 



Instructions (refer to Fig. 15) 



1. Cut a 29 cm length of cotton line. 



2. . Place a lug on each end and crimp firmly into place. 



