Any thoughts on why my Davis solar sensor is reading much to high? Maximum for the day is about 930W/m2 and it’s fairly cloudy so I’d expect it to be a fair bit lower than that. The sensor is currently reading 1730W/m2 so nearly twice as high as it should be. It’s possible that it’s faulty, but can anyone think of any other reason why it might be reading so high? It went high a few days ago but I’ve only noticed today. It’s stayed at about 1700W/m2 for about 48 hours now - even overnight.
It’s not easy to physically examine the sensor because it’s about 30ft up a mast so I’m trying remote diagnosis at first!
I’d better order a new one. The roof is being replaced in a few weeks so that might give me an easier way to bring the mast down to ground level (I need access to a flat roof to help bring it down). It’s probably time I brought it all down to check cabling and the antennas on the mast so other than the sensor cost it’s probably a good thing.
Silly question how do you check the level bubbles on the sensors when there that high
I changed my solar last year as reading were a bit off the uv I changed last month with the rest of the station update
There are alternatives to using an actual solar sensor. Solar-in-a-jar comes to mind. I used one for a short time and found the results acceptable. Another idea I had was using a solar panel output voltage to estimate solar.
I agree the cost for a Davis replacement seems extreme.
The mast that the mounting platform is on is telescopic. I check that the sensor is horizontal with the mast collapsed at ground level so when the mast is extended and mounted vertically it should be very close to horizontal.
I do have a couple of bits of Ecowitt equipment installed but they don’t seem to make a standalone solar radiation sensor and I don’t really want to mount a full Ecowitt station at the top of the mast just to get solar radiation values.
The Davis sensor is expensive but it’s plug and play because it’s replacing an identical sensor.
. . . and it’s probably quite accurate, too. The solar sensor on, e.g., the Ecowitt WS68 is not. And, given that they calculate UV from solar, neither is the UV index.
I have a dilemma! Our roof rebuild is starting today so I put my mind to my station, and in particular replacing the solar sensor.
I looked at the solar value late last night and was surprised to see it was art skit 384W/m2 just before midnight. Still obviously wrong but much lower than the 1700W/m2 that it had been reading. I looked again this morning and it was still the same value, but then I noticed that my uploads had failed the previous day, so the 384 value was from yesterday afternoon. I restarted the software to get the uploads going again, and was surprised to see the solar sensor is working again.
So now I’m not sure what to do. Is the sensor dying, or was it just some kind of glitch that has now fixed itself? I’ve got a replacement sensor now, but is it worth replacing the old one if it’s still actually OK? Or maybe water got into the cabling (I have a joint in the cable) and the recent drier weather has helped get rid of that?
An RJ11 to RJ11 adapter that’s inside a waterproof cable jointing module and then it’s well covered with self-amalgamating tape. The jointing module has rubber gaskets sealing both ends so didn’t actually need the self-amalgamating tape but with the seaside conditions I wanted to make sure the joint would be dry.
That may be a weak point
The rj11 connections may have become tarnished and giving poorer connections
Suggest you change the adapter for a new one and clean the connections on the rj11 plugs even if you fit the new sensor in the end
Davis did sell connector packs that use gel filled splice crimps which I find better
RS still have gel filled splices
How old is the sensor
It’s about 4 years old, but it’s only been up the mast on the longer cable for about 2 years.
I’ll need to re-make the connection if I fit the new sensor so I’ll need a new waterproofing kit. I might try just remaking the connection for now. I still need to lower the mast to do that so I can look at the sensor itself to see if there’s any noticeable damage to it.
