Due to the development of micro system technology (MST), mechanical structures of micro or nanometer dimension can be achieved. Devices in such small dimensions inevitably tend to be affected by Brownian motion and the errors caused by tolerance of fabrication, which decreases the accuracy of sensors. Micro Switch Group Sensor (MSGS) is a new type of sensor system which works by exploiting the stochastic features of noise and randomness within an array of switches. In this paper, the theory of MSGS is introduced. In the experimental work, the theory is verified with three noise affected switches using electronically generated noise. From the analysis, the theory is developed and it is shown that the behaviour of output signals agrees with the theory. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)