PERCOS-Performance Coding System of Methods and Devices Used for Measurement and Control

This paper describes a classifying and coding system of functions and performance characteristics of devices in a way that is useful to the systems designer, who must select a chain of compatible instruments to achieve a measurement or control system of prescribed accuracy and reliability. The performance coding system consists of numeric codes for rating a device in terms of twelve parameters of importance to the over-all performance of the system, such as precision, stability of calibration, rate of performance, useful shelf life, mean operating time to failure, average repair time, cost, availability and physical volume. The numeric codes provide a quantitative description of the performance data to the nearest order of magnitude only. However, this broad classification is consistent with the magnitude of the expected span of performance data of all the devices in a complex system. An edge coded card system is described for the selection of devices or methods complying with the performance parameters. The individual card specifies the exact technical data of the device, the input and output requirements, and especially the environmental conditions under which the performance parameters are given. This classification is established for and with the cooperation of IRE Subcommittee 10.3 of the Industrial Electronics Committee.