Abstract: Material samples may be tested for weathering by a method which comprises securing the samples to a rack which rotates about a central radiation source, and exposing the samples to irradiation from the source at a first intensity of at least about 1.5 SUNS, while rotating the rack at a rate of at least about 6 rpm. Alternatively, a lower radiation intensity may be provided from the same apparatus, using a lower rotation rate. The method may also comprise a step of varying the inductance of a circuit supplying power to the central radiation source as one changes the intensity of the irradiation, to enhance the constancy of spectral distribution of the irradiation at the different intensities.

Abstract: A weathering testing machine or the like is provided with improved stabilization of conditions such as temperature and humidity, coupled with more accurate readout from sensors on a moving member in the machine, and other sensors and microprocessors.

Abstract: A weathering testing machine or the like is provided with improved stabilization of conditions such as temperature and humidity, coupled with more accurate readout from sensors on a moving member in the machine, and other sensors and microprocessors.

Abstract: A weathering testing system comprises a rack for carrying samples to be tested with the samples having inner-facing surfaces, and a lamp centrally positioned of the samples. Blower means are provided for directing a stream of air through the rack. By this invention, the rack may be relatively rotated with respect to the stream of air to provide added uniformity of blowing conditions to the samples. Also, the lamp may be positioned in an adjustable manner so that it can be placed parallel to the rack for optimum radiation. Also the fitting which holds the lamp may be modified so that the lamp may be installed in only a single rotational position, for increased consistency of light irradiation, which gives more uniform calibration. Likewise, an automatic technique for determining ignition and operating of the lamp is disclosed, where a current sensing system found in prior art units can be dispensed with.

Abstract: A lamp cooling system is provided in which a liquid-cooled lamp is connected to a flow circuit conduit for cooling liquid circulating through the lamp. A liquid/air heat exchanger is positioned in the flow circuit conduit to cool liquid flowing in the flow circuit conduit by heat exchange with air.

Abstract: A radiation sensor comprises a housing, a radiation filter, and a photocell positioned to sense radiation passing through the filter. Means are provided for receiving signals from the photocell indicative of radiation sensed by the photocell. In accordance with this invention, means are provided for hermetically sealing the filter and photocell from the exterior, and also for providing cooling (and optionally heating) of the filter and photocell to hold their respective temperatures below predetermined maximum levels, for improvement of sensing accuracy and operating life.