A detection system for detecting gamma rays including a scintillator crystal for receiving at least one gamma ray and generating at least one ultraviolet ray and an avalanche photodiode for detecting the ultraviolet ray. A sample having planar sides and a sidewall extending between the planar sides is placed in a fixture so that the planar sides are confined. The operating member is supported on a steering hanger beam in the rear of the control lever to swing the control lever forward in response to rearward movement of the dashboard upon frontal collision of an automobile. The solenoid-operated pilot element is movable between a first position at which pressurized fluid from the inlet pressurizes a control chamber in communication with a control end of the main poppet to urge the main poppet toward the flow-blocking position, and a second position at which the control chamber is communicated with a drain to move the main poppet toward the flow-passing position. The pre-printed portion may be a regular dotted pattern. Moreover, an offset current is pulled from a detection input of the double sample amplifier in order to generate a more accurate DC output voltage.