Abstract: A barrier device threadably mounts to a cabling aperture on a field mounted transmitter. The field mounted transmitter receives and transmits signals, and is wholly powered by a current loop circuit. The barrier device has a conductive housing with at least a first and a second aperture and a pair of conductors passing through the first aperture of the barrier device, for connecting to a terminal block in the transmitter. A pair of signal terminals, preferably as ring tongue lug, is mounted in the second aperture of the barrier device. The signal terminals are connectable to a handheld communicator, which is used to calibrate, monitor and test the transmitter. A barrier circuit is mounted in the housing and is electrically connected between the signal terminals and the conductors. Signals from the communicator access the terminal block through the barrier circuit, and the barrier circuit limits the power available at the signal terminals.

Abstract: An adapter for coupling a pressure transmitter to a vessel or tank carrying a liquid therein that establishes a hydrostatic pressure at a flanged opening has a planar surface that includes two spaced apart pressure ports that are aligned with and will mate with the isolator input ports of a differential pressure transmitter. The pressure ports are arranged so that the transmitter can be mounted very close to a side wall of the vessel or tank, with the hydrostatic pressure sensing port positioned closest to the vessel to eliminate errors caused by tilting of the adapter and transmitter from bulges that may occur in the vessel or tank side wall. Additionally, the adapter planar surface mounts the transmitter facing sideways, where the transmitter can be quite easily serviced, replaced, or examined.