Abstract: A compact, ambient light sensitive flashing warning light that is removably attached to a traffic control device to alert on-coming motorists and pedestrians of a roadway condition. A photocell is connected between a light bulb and a battery voltage source so that illumination of the bulb can be made dependent upon ambient light conditions. The warning light includes a tapered attachment leg that is sized to fit through a hole in the top of a conventional hollow traffic cone, such that the warning light is removably attached to the cone by friction. As an alternate embodiment, the warning light may be interfaced with a bracket that is adapted to be fastened to other traffic control devices such as a conventional wooden barricade.

Abstract: A hand held electronic grading level which automatically and accurately calculates the grade of a ground plane and indicates whether said grade is level. The grading level comprises a telescopic site level and a sonar system that is coupled to a microelectronically controlled calculator and a digital read out display. The sight level permits the grading level to be aligned horizontally with a distant sight target. The sonar system then generates an acoustic pulse which is reflected off the ground plane and received at a detector. The elapsed time between the transmission and receipt of the acoustic pulse provides an indication of the vertical elevation from the gorund plane to the sonar system. This elevation is displayed and compared to the known elevation of the distant sight target. The deviation between the shot and known elevations is also displayed to indicate the actual grade of the ground plane and whether said ground plane is level.