The IEC Multi Counter with frequency, Geiger counting and audio amplifier with speaker is the most powerful of all the IEC Timer range. It is 220/240V.AC mains operated with a bright red LED display and sloping front panel for ease of using and viewing. It is a fully featured fast Timer with 20 memories and the same performance as the 4063101 but it has power for PhotoGates on the front panel. It is complete with Geiger tube output with adjustable HV to the tube. The suitable tube and cable is 1885050 (not supplied). A special output is provided for a 'solid state Alpha Detector', but this device is no longer available as an accessory. Geiger counts can be measured over preset times, rate/S or continuous. The audio amplifier has volume control for the internal speaker and 4mm sockets for output to oscilloscope.