New sunphotometer for network operation.

A handheld sunphotometer has been developed and is described. It operates for 9 wavelengths in the visible and near infrared. The sensitivity range is rather broad, so it can be used in turbid as well as clear atmospheres. The operation is simple, and a digital readout helps prevent operator biases. The instrument is sun powered and suitable for network operations. Determination of the atmospheric turbidity due to aerosol and the column content of O3, NO2, H2O is possible.