We'd like to use analytics cookies to understand which symbols people look up, so we know what to research next. They are not used for advertising and we set none of them unless you say yes. What we store.
A plain circle marking an instrument out in the plant.
Also known as: Local instrument symbol, Field instrument bubble
On a piping and instrumentation diagram a plain circle denotes an instrument mounted in the field, at the process rather than in a control room.
Denotes an instrument mounted at the process, accessible only by going to it.
Contexts: Technical drawing
Is distinguished from control-room and shared-display instruments by the lines drawn across the bubble, which encode where the instrument is accessible from.
Contexts: Technical drawing
A plain circle with no line across it, containing the instrument's tag letters and number.