The ‘Virtual’ make Sun-Shine Recorder is manufactured to a proven design and is of the type used extensively by meteorological services. Basic Main Components are bowls which are manufactured from Bronze as per IS:306:1968 and are precisely machined and assembled. The sphere bowl is made uniformed and well annealed and air bubble free glass having good surface finish. The instrument is always supplied with one year recording graph, and standard stenciled curve for comparison. The sphere, made of well-annealed colorless optical glass is securely clamped on a semi-circular metal arc by means of two bosses attached precisely across a diameter and located by an adjusting screw onto the ball ended boss. Also mounted on the arc is a bowl of spherical section machined from gunmetal.