WH3081 Data Sample Rate vs Transmit/Update Interval

[siers]

Hi Everyone,

First time posting here about my WH3081 weather station, and hoping for some help after not being able to find the answer through searching.

Now I'm aware that the weather station wirelessly transmits/updates the base station every 48 seconds. However, I want to know us the weather station itself always collecting/sampling data during this time? And is it recording the changes as they happen or just sampling the data every 1 second?

For example: Hypothetically, the wind is blowing at a constant 20km/h and the weather station gets a wind gust of 50km/h between the 48 second transmit time. At the next transmission of data, will the weather station have recorded the 50km/h wind gust or just sample the wind at the time of transmission?

Hope this makes sense, and once I know the parameters it will help diagnose a problem I'm having with the rain gauge.

Cheers
Jeff

[steve]

As far as wind speed is concerned, the sensor is simply counting the rotations of the anemometer. It then calculates the wind speed by using the number of rotations over a given period.

The 'speed' value that the console displays is calculated from the number of rotations over the 48 second period.

Within the 48-second period, the sensor will also be counting the number of rotations over a set of smaller intervals. I can't remember whether anyone worked out for certain exactly how many intervals it uses, but it will presumably be something like six 8-second periods, or 24 2-second periods, etc. It reports the highest of that set of figures taken in the 48-second period as the 'gust' value.

The rain sensor just works by counting tips and keeping a running total; it transmits the current value of that counter every 48 seconds.

[siers]

The rain sensor just works by counting tips and keeping a running total; it transmits the current value of that counter every 48 seconds.

Thanks Steve, that's the answer I was after (and expecting).

Reason for saying that, during the constant, heavy rain last Friday night here on the Gold Coast - the weather station was indicating 0.0mm/hr and didn't count any rainfall for the night. It then started working again the next morning during some light rain and showers - but I suspect the readings are lower than what's actually happening.

I've checked twice that the rain sensor is clean and the internals are clear of any insects, debris and manufacturing 'blobs' that would stop the tipper. When I slowly pour water in the gauge I can hear it tipping and it does record some data.

Anyway I asked the 'eBay' seller for some assistance with what I described above, and was simply told "the rain guages scans once every 45 seconds only so if there is a quick downfall it might not register as expected." Obviously not correct (especially during the constant rain!) but wanted to confirm first.

How can I test the accuracy of the gauge? Should I pour water in the gauge, count the tips and then multiply by 0.3mm? Or will pouring 100ml of water correspond with 100ml of rain (I presume it's not that simple based on the funnel surface area).

Cheers,
Jeff

[mcrossley]

The area of the FO rain gauge is 5500mm² so in theory 1 tip = 0.3mm of rain = 5500 *0.3 = 1650 mm³ = 1.65cm³

So a reasonable number like 20 tips = 33cm³ of water ~ 6mm of rain

Though I have never tested it myself