Inspeed Vortex & HB Anemometer Control Board odd behaviour when it rains?

I have a Vortex and e-Vane connected to one of the new Hobby Boards Anemometer Control Boards (ACB). I’m reading the values using OWFS and custom software on an ALIX1D with a view to feeding the data to Meteohub and from there to WD. The combination is working great, except when it rains!

I am querying this on the Hobby Boards Forum and by mail with Inspeed but wondered if anyone here had any ideas, so here’s the detail:

Since installation on the mast (10m fibre glass) it has rained on the 3 occasions. Only around 0.5mm (0.02") per hour for around an hour each time, so pretty light rain, but on each occasion the Vortex/ACB combination has suddenly started reporting around 10 times the number of counts that actual rotations would account for (I can see the anemometer, and there is an Oregon Scientific WMR928 anemometer mounted lower down the same
mast), e.g. over 100mph in place of 10-15 mph. A while after the rain stops, normal reporting of wind speeds resumes.

So far as I’m aware all connections are waterproof. The Vortex end is as supplied. The standard 25’ wire is joined to an extension which is ~10’ of 6 core (2 cores for the Vortex, 3 for the e-Vane, 1 unused) alarm cable inside a small IP55 box with all wires entering from the bottom and the joint itself sealed with liquid electrical tape. The extension joins to the ACB inside an IP65 box close to the base of the mast, again the cable enters from the bottom, in this case the connectors are coated in dielectric grease. In both IP boxes the eVane connections are on the same cable and connector blocks as the Vortex ones, and the eVane has behaved fine throughout.

There are no obvious sources of RF in the area (assuming that the WMR928 anemometer Tx isn’t powerful enough to be significant), and it only happens when it rains (so far).

Does anyone have any ideas about cause or cure?

A few random thoughts I’ve had include…

Could the ‘wet pole’ be acting as an antenna and picking up RF which then gets passed on to the wire? If so maybe it would help if I replaced most of the wire from the head to the ACB with twisted pair (I have some UTP patch, ans some FTP solid)?

I know the “serial plug” Vortex has a small capacitor between the wires at the plug end. I’m not an electronics guy so I’m not sure of the logic behind that. Maybe some sort of smoothing or amplification? Might adding one have some role here?

Since you’ve covered the waterproofing issue and it’s a fiberglass pole I would suspect precipitation static (used to call it static rain but some rock band wins in google searches for that). Do you have any radio receivers you could take a listen to next time it happens?

Thank you. Googling ‘precipitation static’ brings up lots of relevant looking stuff.
Looks like shielded cable might help, plus something to help improve discharge - though ‘grounding’ a dielectric material could be interesting! Maybe a grounding wire running down from the (aluminium) anemometer bracket?

Only standard ‘domestic’ FM/AM radios (both mains and portable).

Grounding wire is worth to try I think.

Tuning a portable AM radio to a gap between stations should work. Try it when it’s not raining so you have a baseline.

I have essentially the same setup and I do not get this problem. The differences are that my wind pole is metal and I have it grounded with scrap copper strip buried in the ground. The standard 25’ Inspeed cable reached my junction box so I have not extended it. Of coarse, it is also inside the grounded pipe. I have had several periods of light rain since installing the HB wind board but haven’t seen anything like what you describe. I also wondered about the capacitor across the Vortex inputs to the Windworks box which I no longer use. But I have not used one in this setup.
My HB windboard/Vortex/E-Vane has now been running continuously for 20.5 days and 1,700,000 data points without a single glitch.
w0mbat

Yes, I don’t think this is at all a generic problem. I am very happy with the Inspeed / Vortex combination and am convinced that it is ‘good gear’. I just happen to be using it in a combination of circumstances that have unearthed (no pun intended!) a weird problem.

An interesting idea. I’d need to drill my pipe to do that. I think I’ll stick to going down the outside for the present (unless I hear a lot to the contrary).

Thanks for that detail. I’d wondered if the Windworks box used a capacitor too.

More rain this morning and the good news is that if I used the formula
isRaining = vortexSpeed > (wmr928Speed x 1.5)
I’d have have an excellent, if elaborate and hopefully just temporary, rainfall detection system, see attached. :lol:

I don’t expect to be able to do anything till the weekend, but it the weather is okay then my current plan is to lower the mast, then:

a) Run a wire from the anemometer bracket to an earthing rod at the base that I’d already got ready for use with a HB lightning detector.
b) (Probably) replace most of the vortex to ACB wire run with FTP (foil shielded twisted pair).

For the grounding run I have some “2.5 Twin & Earth” (no idea what that would be called outside the UK) stashed up in the loft from when the house was last rewired. That’s has 3 good thick conductors - maybe thick enough that I can arrange for one or more cores to reach out and past the anemometer so that it is not itself the high point, though I’m not sure if that would be worth it?

The FTP may be belt and braces, but I figure that it is unlikely to make matters worse, and it would be sad to raise the mast and discover that I then needed to lower it and try something else. I have a feeling that it might be an idea to ground the FTP shield too?

One other thing I wondered about was if it might be an idea to bond the (metal) spiders & guys to the grounding wire too?

How does that sound?


Oh no, yet another home made sensor for WD to handle #-o :lol:

"2.5 Twin & Earth" (no idea what that would be called outside the UK)

From the Department of Useless Information You’ll Never Use that would be “12/2 Romex (with Ground)” here. 2.5 would actually be 13 gauge but the options are 12 (20A) and 14 (15A).

Rest assured I’ll not be making that one a “Feature Request”. :lol:

Thanks for the translation on 2.5 Twin & Earth.

a) I’ve spoken to the original supplier of the fibreglass mast. They mainly deal with radio communications and are very familiar with “precipitation static”. He’d never come across this variation before, but could see the equivalence.
He thinks that grounding the anemometer bracket is an almost certain cure (but likes the idea of taking the wire down inside the mast too).

b) Over on the Hobby-Boards forum someone commented on a case where a rain gauge at the end of a long (over 30’) wire was over reporting, i.e. another counter connected to a reed switch by a long wire pair. That problem was traced to the rain gauge sharing a ground with an electrically noisy system nearby. The solution involved giving the gauge its own ground and making sure that was the only ground in use. They also used a shielded grounded (same ground) cable, and added a 100 ohm resistor in series with one conductor of the pair to help with the long run’s capacitance. I hadn’t come across the resistor idea before.

Are there any electronics in the anemometer body, or is it just a reed type thing? Could be worth trying the few turns on a ferrite trick too.

Hi again skyewright.
Just a couple of points:-

My point about my cable running down the inside of my grounded metal wind pole is that it is very well shielded by the pipe itself… one of the main advantages of a metal wind pole. I don’t think putting your cable inside your fibreglass pole will make any difference.

Something else you may wish to think of while you have you windpole down…I was underimpressed by the flimsyness of the E-Vane right angle mounting bracket. My concern was that it was very “resonant” ie it would vibrate. My view was that wind rushing over the mount was likely to induce resonant vibration which would be bad for the bearings in the long term and possible introduce other unimagined problems. I happened to have some aluminium strip similar to what Inspeed use for their brackets so I easily bent up a brace between the pole and the horizontal part of the E-Vane bracket thus forming a triangle brace. I bolted it to the same points on the pole as the standard brackets and attached it firmly to the horizontal bracket with cable ties.
The whole assembly is now well braced and less likely to vibrate.
I may be a pedant but you may think this worthwhile.
w0mbat

ps Niko, the Vortex is just a reed switch…nothing else.

Thanks.

Hmmm, I see the HB board will count up to 2kHz. At 2.5 mph/Hz (inspeed spec) that would be 5000 mph so the input can stand some filtering for this application :lol: RC and/or ferrite would be OK.

Only a reed. Simplicity and minimum cross section (aside from the obvious need for cups!) are among the appeals of the vortex.

I do happen to have 2 spare ferrite rings handy (Maplin QT26).
Is it relevant if there is only a reed up there? If so, which end to use at, or both?

Yes that makes sense, and in a way I’m glad to hear it as I don’t really like the idea of 10m of unsupported wire dangling down a mast that even with guying is bound to move at least a little.

I wouldn’t call that pedantic. I have a strong tendency towards ‘belt and braces’ myself. Way back when I went to university I studied Civil Engineering, maybe that influenced why I like the idea of substantial fudge factor safety margins. :lol:
I don’t have any aluminium strip, but I do have some 12mm aluminium angle that might be adapted for such a purpose. I’ll ponder on it. Thanks for the thought.

Last night just at the start of a ‘rain event’ in flat calm conditions I spotted a reading of 0.0mph gust and 5.4mph wind. Because I wrote the code that reads the data I can tell that that means there must have been a leap in count of just under 130 in the fraction of a second between 2 sections of code.

Anything above 60m/s => ~134mph => ~54Hz average on 3 second gust measurements gets reported as “out of range” at the Meteohub stage (I only show Meteohub the highest 3 second gust in each minute) . Similarly error checking on ‘wind’ (which I measure over 60 seconds) regards anything over 50m/s => ~112mph => ~45Hz average as “out of range”.

The Meteohub error log does report some out of range values, but not vastly out of range (I’ve not noticed anything above an equivalent to around 60Hz average).

That is very limited and somewhat circumstantial evidence, but I think it does tend to suggest that the extra counts are arriving as discrete and (relatively) high frequency bursts. If my understanding is correct I think that supports your idea of using a ferrite to help filter out the bursts.

If you try ferrite I would put it at the electronics (non-anemometer) end, then it would help to block anything picked up on the wire, I would try a capacitor across the line too. Looking at the pic in the HB manual it looks like the inputs have series resistors but (unless they are on the other side of the board) no capacitors.

How long is the cable?

Another thought just occurred to me. Do you have any overhead power lines close by? Dirty insulators will cause discharges when wet.

I’m glad you said that. The wire at the top end has a pretty stiff outer layer. At the electronics end the wire is much more flexible.

I don’t recall there being anything on the reverse side of the board, certainly nothing looking like the usual “can” style capacitor.
What sort of size?
IIRC when munrobaggings had a look inside the plug on his “Vortex with serial plug” he found a “K5U 105M EC1” which I think translates to “1uF +/- 20%”?

~35’ anemometer to control board.

The closest domestic supply overhead line is maybe 40m (130’) away? The next higher grade line (with a “step down” to our line) ends around 50/60m away.

Yes, that’s a 1 microfarad. Theoretically a 1K series resistor and a 1 microfarad cap would make a cut off at 160 Hz (calculator here) so I think that’s in the ball park, could even be a bigger cap, but without knowing exactly what the input circuit is it’s a bit of a crapshoot. Either way hanging 35 feet of wire off the input without some filtering or other tricks is asking for trouble IMHO. Probably be better if the board was up the pole and the connection back was 1-wire but that would open a whole other can of worms.

Thank you. I’ll try something like that once I get a hold of a suitable capacitor.
In the meantime I’ve already fitted the ferrite ring.
It would be interesting to see if that had an effect on its own, but from the forecast it may be several days till we see rain again. Maybe I’ll have the grounding in place too by then.

Maybe, but as the Vortex comes with 25’ as standard and can be ordered with up to 200’ I’ll probably not be the only one to try it (though the fibreglass mast may be an unusual ingredient).

When I first completed the cable run from mast to computer, but before I fitted the ACB into the box at the base of the mast to house the 1-wire ACB board I tried a couple of experiments with a simple connection using the full length from masthead to computer. Connecting the vortex and eVane direct to the ACB with the full 160’ of wire was fine for the eVane, but the anemometer count was around 20 times too high presumably just down to various electrical noise (no rain in sight). However if I switched the anemometer pair over to the humble ‘bicycle computer’ that came with my Vortex, that managed just fine; maybe the ‘bicycle computer’ has some filtering built in?

Eric wondered about that option too, but I want to avoid it if at all possible.
I do hope to be adding a few other 1-wire things to the mast that will include mounting circuit boards (e.g. HB lightning counter, and some sort of sunshine measuring device), but I expect those to be reachable from the base (at most with the aid of a short ladder), not anywhere near the top of the mast.

Hopefully the various grounding and filtering techniques will sort it out. Time will tell…