Abstract: A fluid pressure sensing device for a fluid-containing vessel, and a method of assembling said device, is disclosed. A metallic diaphragm is preferably laser-fused to one end of the sensing device to define the end surface thereof. The sensing device is preferably mounted and sealed with the wall of the vessel such that the diaphragm and such sealing engagement is substantially flush or coplanar with the inside surface of the wall. A passageway extending through the sensing device admits an indicator fluid to one side of the diaphragm for measuring the pressure of the fluid in the vessel. The passageway also includes an adjustable nozzle for pre-calibrating the sensing device.