Abstract: A solenoid operated distribution valve for supplying a servomotor in a trailer with a sway control braking signal in response to a sway signal being evaluated in a comparator. A wave spring surrounds the plunger of the solenoid to nullify the movement thereof such that the output force which operates the distribution valve is a direct function of the sway signal.

Abstract: A readily portable ultraviolet radiation monitor includes an ultraviolet radiation sensitive cell or transducer arranged in an electrical circuit to drive a digital voltmeter. The ultraviolet sensitive transducer includes a solar blind vacuum photodiode which is exposed to the area of interest through various ultraviolet filters to produce a desired predetermined transducer response characteristic. The monitor is generally T-shaped with the transducer located to view out of one arm of the T, while the meter display is viewed into the other arm. A dependent handle comprises the leg of the T.