Abstract: A pressure gauge includes a cylindrical member having a flexible plate covering one end. Center flex of the plate is used to measure the force applied by fluid pressure. A low pressure transducer electrically measures the applied force. Pressure is transmitted from the flexible plate to the transducer by hydraulic fluid enclosed in the cylinder by a plastic boot. The boot is sealed to the cylinder by a sweat fit between the cylinder and a coaxial collar. The range of forces that can be measured is controlled by the thickness and diameter of the plate. In addition to pressure, the gauge can be used to measure temperature and orifice opening, and provide an indication of volumetric flow of the fluid.