Lambrecht Sunshine Recorder Cards Recording cards for sunshine recorder
The Lambrecht sunshine recording cards are made from a special board with matt turquoise finish on which even weak sunlight produces a clearly visible trace. They are specially treated to char rather than burn so that the trace produced by strong sunlight does not spread significantly.
Each pack contains three types of card to correspond to the behaviour of the sun at different seasons: long curved cards for use in summer (UK 12th April to 2nd September), straight cards for use near or about the time of the equinoxes (UK 1st March to 11th April; 3rd September to 14th October) and short curved cards for use in winter (UK 15th October to the last day of February).
(100 pc for winter; 100 pc for summer; 100 pc for spring & autumn )