A pressure measuring device generally consisting of a very carefully calibrated bourdon tube. A pointer or indicator is fixed to the free end of the tube, and will register the pressure within a container or pipe to which the gauge is connected. This gauge normally does not measure atmospheric pressure. These
gauges are frequently referred to as spring gauges or as Laboratory test gauges, and are also identified by a pressure rating of 30#, 60#, 100#, 500#, and so on. This pressure rating is the highest pressure the gauge will measure.