Abstract: A light and weather resistance testing apparatus (9) is provided with a sensor (1) located in the plane of the testing samples (14). The sensor (1) uses a transmitter (4) for wireless transmission of signals representing radiation received to an antenna (3) disposed on the wall (8) of the apparatus housing. The sensor (1) has multiple receptor cells (6) for various spectral ranges. The sensor (1) is powered by solar cells (7) located on the sensor housing. A plotter and display unit (13) can be connected to the apparatus for read-out of irradiance and irradiation. The wireless transmission of data from sensors to the display unit permits continuous measurement during rotation of samples and sensor.

Abstract: In a heating and/or cooling system, two heat transmitting media are blended into a blended medium with adjustable temperature. The motor (M) of a blending member is controlled pulsewise in both directions by comparison pulses from a setpoint/actual value temperature comparison.In order to provide a system which is simple to construct, which is wear-resistant and which permits a quick and accurate adjustment of the blending member, the circuit arrangement for controlling the motor (M) contains a first pulse generator (TB1), which generates pulses of constant width commencing respectively with the end of a comparison pulse and is connected to second and third pulse generators (TB2, TB3). The second and third pulse generators (TB2, TB3) generate pulses of a width proportional to the actual value or the setpoint of the temperature, respectively, which directly control the motor (M) after comparison in a comparator (CO).