11 



6. Return the plastic cover to the relay. 



7. See below for attaching the relay to the sensor housing. 



Wiring the Relay 



Materials 



(1) PVC test cap 



(1) spool of 16 gauge stranded, two-conductor speaker wire 



Instructions (refer to Figs. 13, 14) 



1. Cut slits in the PVC test cap so that they correspond to 

 prongs on the relay (c. Fig. 13) 



2. Insert the relay prongs through the slits in the test cap. 



3. Cut the two-conductor speaker wire to a length long enough 

 to extend from the sensor relay through the PVC 'T' (see Fig. 

 14). 



a. Sever the positive (copper) lead and connect the cut ends 

 to the relay as follows: 



(1) Solder one cut end to the 2nd position contact. 



(2) Solder the other cut end to the 3rd position (contact 

 plate with copper strips). 



(3) Apply silicone cement to the soldered connections. 



Attaching the Sensor Relay to the Sensor PVC Housing 



Materials 



(1) PVC adapter with plug 

 (1) PVC elbow (90 degrees) 



NOTE: Use 3.8 mm diameter stock for all polyvinyl chloride 

 (PVC) components. 



Instructions (refer to Fig. 15) 



1. Drill a 6.0 mm hole in the rim of the sensor elbow to corre- 

 spond with a. Fig. 15. 



2. Secure the sensor relay against the PVC test cap. 



a. Add silicone cement to the test cap/relay interface. 



b. Bend the unwired prongs firmly against the test cap. 

 NOTE: Make sure all electrical wiring to the sensor relay is 



completed before the relay is secured to the elbow. If a 

 spore trap or other instrument is to be activated during 

 periods of leaf wetness, it should be wired to the sensor 

 relay before the relay is cemented to the elbow (see 

 section, 'Attaching a spore trap to the instrumentation'). 



3. Extend the hooked wire through the 6.0 mm drilled hole, and 

 then carefully seat the sensor relay/test cap in the elbow. 



