Author Topic: intermittent soil sensor  (Read 613 times)

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Offline Aardvark

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intermittent soil sensor
« on: May 23, 2014, 12:32:59 PM »
I knew when the wife woke me up out of a nice dream today was going to be one of those days.  I have a soil moisture sensor that intermittently stops sending data, then it kicks in.   Not the transmitter as I get everything else.   I think it might be a short in the wire splice,  it is at 8 inches so it won't be that big of an issue to pull up and see.

I will have good values, then suddenly dashed out data and then it comes back.   I have checked the other probes to the station, the temperatures, other readings, checked between Envoy's and console, and it all shows the same stuff.   

I don't believe it is the station as it was refurbished by Davis last year.   Well, I need a project so up it comes, rinse off  then down to the shop to see what the problem is.   I bought a probe off Ebay and it turned out to be a 5 foot lead, so I soldered and ran the cable up the pvc.  I am wondering if I didn't wrap the splices well enough.  I used electrical tape around each wire, then self fusing silicone tape around the whole thing. ( http://www.uline.com/BL_6422/Silicone-Self-Fusing-Tape). 

I am thinking that maybe the wrap has been punctured enough through the tape that I am getting a short.  The slight change in temperature might be doing it, although, I don't see any pattern.

Davis VP2 Plus; 24h  FARS; Extra Temp Humid sensor (2); Extra Temp Station (2); Soil Moisture/Temp  https://www.weatherlink.com/embeddablePage/show/1c484adbfa914d1aa10a58ad53ccd563/summary;Weatherlink IP;USB; MAC Catalina
; Webcam;

Offline Aardvark

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Re: intermittent soil sensor
« Reply #1 on: May 24, 2014, 04:40:00 PM »
I spent 30 minutes with the multimeter and concluded the probe is fine, but somewhere between the probe and the solder joint, there must be a broken wire,  couldn't get consistent readings.

I went to the hardware store, bought 20 feet of copper solid core/2 pair/ thermostat wire.  cut the wire 4 inches above the probe, wrapped, soldered and double wrapped the splices,  re-ran the wire in the conduit and I think it is working.

Funny how the wire that comes with it is stranded and it is fragile somewhere, rather than buying a new probe,  I did repair  this one.  Now to wait it out to see how it works.
Davis VP2 Plus; 24h  FARS; Extra Temp Humid sensor (2); Extra Temp Station (2); Soil Moisture/Temp  https://www.weatherlink.com/embeddablePage/show/1c484adbfa914d1aa10a58ad53ccd563/summary;Weatherlink IP;USB; MAC Catalina
; Webcam;

 

anything