Pressure and temperature are important safety-related parameters. The two parameters are closely linked in systems where gases or vapours are present, with behaviour governed by the combined gas laws. The temperature is also critical in mechanical systems that can overheat, like motors or bearings. Monitoring temperature or pressure requires the correct selection of instruments.
Read MoreUnderstanding safety functions: Safe speed and safe standstill
In this post, I’ll discuss two safety-related parameters: safe speed and safe standstill. Speed control is a very common machine function. Conveyors, mixers, pumps, and many other applications rely on variable-speed drives. Some speed parameters are also safety-related because variations in speed can increase the risk to workers. See this post for more information on…
Read MoreUnderstanding safety functions: Response time
This post deepens the discussion of safety-related parameters. Safety functions are control functions whose failure causes an immediate increase in risk. ISO 13849-1 [1] defines several common safety functions to develop safety-related control systems. In this post, I will discuss the response time safety-related parameter.
Read MoreUnderstanding safety functions: Safety-related parameters
Safety-related parameters are control system variables whose incorrect setting immediately increases the risk to the user. Some of the most common include safe-reduced speed and safe standstill, but temperature, pressure and other process parameters can also be safety-related. Defining what machine parameters are safety-related and then designing control hardware and software to meet the functional…
Read MoreUnderstanding safety functions: Local control
The local control function is important to understand when designing machinery control systems. If the failure of the local control function could lead to increased risk to the user, it is a safety function. This article explains the local control function from a functional safety perspective.
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