Davis Analogue and Sonic Anemometer Reviews

Davis Instruments supply two forms of Anemometers an older Analogue and a more recent Sonic one. The mechanical version has been changed over the years to make them more reliable. The original model used a Reed switch and magnet to measure the wind speed and as the cups rotated the magnet would close the switch creating a pulse which Davis ISS counted. The Wind direction uses a potentiometer to measure the wind direction and this hasn't changed over the years. A big problem with the reed switch that it failed fairly quickly which briefly allowed some people to offer an after market repair service. The newer version uses a hall effect to measure the wind speed. The newer version wind vane has a brass tip. For more details visit this page. There has been reports of the Wid direction failign due to the potentiometer wearing out but this is fairly rare. However if it does fail there isn't any replacement and you have to but the whole unit.

The Analogue version can be seen on the left. Over the years I have gone through several of these Anemometers. As I mentioned earlier the early designs had a reed switch and this tended to break after a year perhaps two resulting in intermittent readings or zero readings. Reliability improved with the newer version but is still a long way from being called reliable considering the price. The other problems I've had is the sun ultraviolet taking out the plastic housing this totally wrecked the unit due to the fact that you couldn't replace the wind direction. The other strange failure was with the Wind speed cartridge that had worn away the of unit so the whole cartridge was full of old plastic jamming it. Clearing it out fixed it and there as a spare.

Davis a few years back introduced based on the LCJ Sonic-Anemo-DZP. The main advantage of this unit is that it has no moving parts so should in theory be more reliable. The unit has a rechargeable battery which is charged by the solar panel on top of the Unit.

I would have liked the battery to be placed in an external box rather then inbuilt into the unit which makes it difficult to replace unless you modify the unit and void the warranty. How long the battery lasts is another question as to how easy it would be to replace. The unit is on test and I have decided yet whether to make it my main instrument or not. Since I have a weatherlink live I can use both units where the consoles can only use one.

Setup and calibration of the Davis.

You need to decide where to place the Anemometers. A guide can be found here You need to also think about access so if you go for the roof mount and you're no good with heights then you'll need call in an engineer. They'll also need to be able to line the unit up with the north so you'll need to guide them in this matter. Since there's a good chance the analogue version will fail at some point and if you have room I g suggest mounting on a pole with enough clearance to prevent the unit from being sheltered. In theory reliability shouldn't be an issue with the Sonic version but you'll need to take it down to replace the battery. At the moment there's no guide as too how long the battery will last. Once you got the location sorted then you'll need to plug the unti into the ISS or a Davis Anemometer repeater which is really another ISS unit.

Follow the instructions to setup the console and then you'll need to make slight adjustments for the wind direction as this will never be right unless you're extremely lucky and also on Davis weather link website. This can be done in the software and also on the console. .

Day to day running of the Anemometer.

Apart from the reliability of the earlier none sonic until the unit should run smoothly. I've noticed that there is a difference in readings between the Sonic and the Analogue with the Sonic tending to miss the larger gusts for some reason. There's also a difference in the average speed at times as well generally this should be small but I have noticed larger ones. The sonic is better a low wind speeds due to the older one needing more time to ramp up.

Update 14/10/23. I have now removed the Sonic Anemometer the final straw being it missing at 51mph gust recording only 39mph at the same time. The missing of gusts which has been a fairly constant theme and noticed by other users as well means that the Sonic device cannot be recommended.

Common Issues with Davis Anemometer and the not so Common ones.

The older versions showing intermittent wind speed or zero wind speed. This will be due to the reed switch getting stuck. Most of these units will now be out of circulation by now. So if you get a wind speed error is likely to be the cable that has been damaged.

No wind speed and direction not changing. Cable damage or the batteries have gone flat or if you're using a repeater a blown cap. Also flat batteries in the sonic unit. The other reason could be something becoming tangled in the unit jamming. Ice in winter can be problem as well.

Wind speed low and direction not changing or a very silly wind speed in regards to the Sonic. Snow stuck in the cups and blocking the Sonic sensors. Nothing you can do about this until it either melts or gets blown out.

Just a low wind speed showing. This can be due items getting tangled in the unit, Snow again or the plastic breaking due to UV damage and pressing again the wind cups. Bearing issues or physical wear and tear on the wind speed cartridge.

Older version only where the Wind direction flicking to North. This is due to the rare issue of the Potentiometer wearing out or a broken cable.

The embarrassing wrong direction shown. This is where you just misaligned the unit or in the case of the Sonic got the North South mixed up.

Over all Score for the Anemometers.

The jury is still out on the Sonic design at the time of writing /p>.