Abstract: Provided is a targeting system 10 for a robot gaming environment which includes a transmitter 12 on a target robot 16 and a directional receiver 14 on an attacking robot 18 which system 10 is able to ameliorate the accuracy of a firing means of the attacking robot 18. The receiver 14 includes a housing 24 which defines an elongate channel with an opening therein which allows the receiver 14 to only receive electromagnetic signals 20 from the transmitter 12 if the opening is pointed directly at the target robot 16.

Abstract: Measuring cell for determining oxygen concentrations in a gas mixture having a partition consisting of an electrolyte material such as ZrO.sub.2, which reversibly reacts with oxygen and is ion conductive. The measuring cell is characterized in that the partition closes a hollow body and projects therefrom so that the electrodes may be provided on the same side to reduce disturbing influences on the measurement.

Abstract: Physical quantities, such as temperature, mechanical stress, gas concentration and acidity, can be measured by means of elements which generate an EMF as a function of the relevant quantity. In many cases the temperature dependence of the conversion is inconvenient. The proposed temperature correcting circuit considerably reduces the said temperature influence, at least for a given operating range, in that the temperature-dependent internal resistance of the element is measured or used by means of an alternating current and the EMF is corrected by means of this temperature information.