A low-level, high-speed sampling system

Currently available equipment for the high-speed sampling of large numbers of low-level transducers such as strain gages and thermocouples tends to have serious limitations on accuracy and life, or on reliability and economy. A design of equipment for this purpose which is not so seriously limited is described. It combines commercially available units with certain components which have required development. It consists of a low-level multiplexer, dc amplifiers, a second stage of multiplexing at high level, a voltage-to-digital converter, and a recording unit. The design of the multiplexers is described. The low-level multiplexer has accuracy and life exceeding that of conventional units, and avoids the necessity for an amplifier on each input channel. The high level multiplexer has comparable accuracy at electronic speeds. These units are used as building blocks to provide for large numbers of input channels with a high degree of flexibility. Typical system features are described.