Hazard reduction in process plant by instrumention philosophy

Many present-day plant instrumentation, protection and control systems require labour-intensive periodic testing to bolster the user´s faith that the systems remain operative. These test arrangements increase costs and can degrade plant safety. Where such apparatus is used in industrial plant, failures may hazard the plant, the environment and life. Such cases arise particularly in the safety aspects of many industrial processes where dangers exist in the form of radiation, toxic substances, high pressure, temperature or energy. Except in special cases, self-testing, fault-tolerance, fail-safe and similar principles have hardly been applied. This article explores these themes which could, with advantage, be applied more widely and in tandem as means of maintaining process plant in safe service and reducing labour-intensive testing procedures by making all faults safely self-proclaiming