Topic: UV and Solar Radiation sensor readings go haywire...

[piconut]

I've owned my Vantage Pro 2+ for about 18 months now and today I noticed that both sensors have been reading incorrectly for the last several days.  The graph on the top which shows data from both for the last week and has valid data for January 1st, 2nd, and 3rd. However, on the afternoon of the 4th the solar radiation data becomes problematic and never goes below about 700 W/m² and occasionally reads higher. Then on the 6th, the UV joins in the chaos by going to 16 and staying there indefinitely.  The graphs on the bottom show the last 24 hours in slightly more detail.


It should be noted that these sensors are mounted at the top of my roof with the anemometer and then I ran about 100 feet of Cat6 cable to the ISS at ground level.  They seem to have been working fine since I installed then, until just a few days ago. Has anyone seen this before or have a good idea as to where I should start looking?

[LFWX]

The first time my solar sensor gave me errors it was after a few days of wet weather, mine was also installed on my roof with 100 feet of cable. After a few days it started working again.

[miraculon]

I would recommend a shot of CRC QD contact cleaner on the RJ11 connectors in the SIM on the ISS.
After the cleaner, some "dielectric grease" should be generously applied to the contacts.
There might be some other problem with a broken wire or fault in the sensors themselves, but cleaning/grease would be what I would do in this situation.

I bought my can of QD at Home Depot. The dielectric grease is Permatex 22058 which I bought at an Autozone.



Good luck.

Greg H.

[piconut]

The first time my solar sensor gave me errors it was after a few days of wet weather, mine was also installed on my roof with 100 feet of cable. After a few days it started working again.

We did have 1.59 inches of rain this year so far but we've had lots of rain since I installed the sensors and no problem.  That includes at least two times last fall where we got 7 inches of rain in less than 2 hours.  The odd thing is that they both didn't go haywire at the same time, or even the same day for that matter.

[piconut]

I would recommend a shot of CRC QD contact cleaner on the RJ11 connectors in the SIM on the ISS.
After the cleaner, some "dielectric grease" should be generously applied to the contacts.
There might be some other problem with a broken wire or fault in the sensors themselves, but cleaning/grease would be what I would do in this situation.

I bought my can of QD at Home Depot. The dielectric grease is Permatex 22058 which I bought at an Autozone.



Good luck.

Greg H.

Hi Greg...


Thanks for your reply.  I put the Permatex 22058 dielectric grease on both end connections when I installed the wires.  Do you think I should still disconnect it and apply the grease again?  I've never used the stuff before but did so originally on the suggestion of the fine members here that had done the same when they set up their extensions cables.

[miraculon]

If you already applied the grease, it should not need a re-cleaning. There must be another problem.

By the way the font on your reply was extremely small, but I was able to read it by copy/pasting it into Notepad...

Greg H.

[piconut]

If you already applied the grease, it should not need a re-cleaning. There must be another problem.

That was what I was afraid of.  Any idea where I should start?  Is there some some of voltage I can measure at the ISS end to see if it is what should be expected?

[/size]By the way the font on your reply was extremely small, but I was able to read it by copy/pasting it into Notepad...

That was weird. Fixed it, thanks!

[miraculon]

The Davis recommendation is:

Sensor Troubleshooting
If encountering sensor problems, carefully check all cable connections from the sensor
to the console. Cable connections account for a large portion of the potential problems.
Connections should be firmly seated in the jacks and plugged in straight. Try jiggling
the cable while looking at the display. If a reading appears intermittently on the display
as you jiggle the cable, the connection is faulty.

The voltage is 0-3V, but this might be tricky to measure since you need the excitation voltage applied (yellow wire).

I/O Specifications
Green wire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Output (0 to +3VDC); 1.67 mV per W/m2
Red & Black wires . . . . . . . . . . . . . . . . . . . . . . . . . . Ground
Yellow wire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +3 VDC ±10%; 1mA (typical)

Perhaps you could make some kind of breakout cable to monitor the "green wire" voltage vs. ground. This could be as simple as an extension cable and an in-line coupler where you open the outer jacket of the test wire and strip the green and black wires for monitoring.

Also, you should check your Cat6 connections and junctions from sensor to ISS.
I ran about 100 feet of Cat6 cable to the ISS at ground level.
How did you connect the sensor's flat cable to the Cat6 at the sensor end? Is this connection weatherproofed?
Is the Cat6 wire terminated at an RJ11 at the ISS end?

Greg H.

[piconut]

Also, you should check your Cat6 connections and junctions from sensor to ISS.
I ran about 100 feet of Cat6 cable to the ISS at ground level.
How did you connect the sensor's flat cable to the Cat6 at the sensor end? Is this connection weatherproofed?
Is the Cat6 wire terminated at an RJ11 at the ISS end?

To test things originally, I created two patch cables with one set having 2 female RJ11 jacks to one female RJ45 (for the sensor end of the Cat6) and the second patch was a female RJ45 to two male RJ11 jacks for the ISS. On all the connections I used dielectric grease and wrapped the connection with plumber's silicone tape. My plan was to let that run for a week to make sure the 120+ feet of Cat6 wasn't going to create a problem, then cut the ends of the Cat6 and hard-wire the female and male RJ11 jacks.  Well, you know how things go, that was 18 months ago and it is still like that with the patch cable on each end.

[miraculon]

So, if I am reading this correctly, your original RJ11 connectors coming directly from the sensors are still intact?

Can they reach the anemometer transmitter (6332)? You could temporarily plug them directly into the UV and Sun ports on the 6332, then change the "wind" channel on the console to an ISS and disable the normal ISS channel. This would be all Davis wiring with a direct connection from the sensors into the SIM.

You could monitor the behavior of the new "ISS" and the UV/Solar signals and see if it is OK in this configuration.

If so, it should help isolate the problem.

Greg H.

[piconut]

So, if I am reading this correctly, your original RJ11 connectors coming directly from the sensors are still intact?

Can they reach the anemometer transmitter (6332)? You could temporarily plug them directly into the UV and Sun ports on the 6332, then change the "wind" channel on the console to an ISS and disable the normal ISS channel. This would be all Davis wiring with a direct connection from the sensors into the SIM.

You could monitor the behavior of the new "ISS" and the UV/Solar signals and see if it is OK in this configuration.

If so, it should help isolate the problem.

Greg H.

Wow Greg!  Thanks.  I would have never thought of that.  I'll have to wait a few days as we are still having some unusually cold weather along with some possible freezing precipitation here. But as soon as things clear up, I'll do some testing and report back.


Thanks again!

[piconut]

Well I found out that my UV and solar radiation sensor issues were caused by the difficulty that the elctrons had in jumping the gap of the missing wires in my Cat6 cable!  Specifically I had critters gnawing away at a small exposure of the cable.  This is what I found after verifying that the patch cords at both ends were working correctly but the long length of Cat 6 between them was the problem:





I think this is the culprit and he has that guilty look too!





So I spliced and patched the Cat 6 cable and everything is back to working as it should. I also put the small bit of exposed wire into some conduit to prevent it from becoming a meal once again.

[miraculon]

So this is the thanks you get for feeding him so generously.
Maybe vinyl tastes better. It must be like rodent-candy...
Glad you were able to track down the problem.

Greg H.