Topic: Fog Detection Sensor - Does such an animal exist ?

[shopkins1]

I too would like to interface a Fog detector to my Davis Weather stations. Now I am in the apparently enviable position of having 2 Visalia PWD-22 visibility sensors lying around.

I have the manuals which fully detail the protocols, but not the time at the moment.

I could be persuaded to part with one of the units, although they would be expensive to ship outside the UK.

Any thoughts on interfacing to VP2 ? I currently have two ISS, one Anemometer transmitter and one Soil station all transmitting to an Envoy8x, an Envoy and two consoles.

Simon
http://www.wunderground.com/personal-weather-station/dashboard?ID=INORTHYO5

Simon

[wxtech]

The animal did exist 40 years ago when I worked on transmissometers.  That was the system that observers used to calculate Runway Visible Range.  This link to the technical manual may help with the operating principles.
http://www.wxforum.net/wxtech/techdata/images/CDC30250Vol2ch3.pdf     (10MB pdf file)
The technical library is at:
http://www.wxforum.net/wxtech
The system was probably designed during the 1950's.  It used the landing light from a DC-3/C-47 as a light source.  The AN/GMQ-10 was used by USAF and FAA.