Current weather

The Boltwood Cloudsensor monitors the weather above my observatory in real-time. It uses a thermopile measuring the sky background in infrared wavelengths. This value is subtracted from the ambient temperature. If the difference is sufficiently large, (-30°) the skies are clear. If near zero, there is a thick layer of clouds. The sensor will also detect snow or rain and issue a alarm.

A dedicated PC is running 24/24 using home written client-server software. This application monitors the conditions real-time and writes the results to a Microsoft Access database. Apart from saving the weather conditions, the server application will also update a chart. The chart and the monitor form are saved to a .jpg and published to the web every 5 minutes. Using a database enables the client to check the current conditions. The client can be anywhere as long as there is a connection to the database. This client will generate user settable alarms. When clouded the software will generate a alarm following an amount of time that the skies were clear. This prevents being waked up for minor clearings. Most of these settings can be user modified.

The sensor is reliable and stable. It performs exactly as advertised. The only type of clouds that are undetected are thin, high cirrus clouds.

Here is my review with more details