The Excel Industries range of back & bottom inlet Bourbon type combined pressure and temperature gauges are an economical gauge suitable for displaying the pressure in both water and air piping systems. The Bourbon tube which is an elliptical copper tube sealed at one end flexes when pressure is applied. As it flexes the linear movement is changed to a rotational one by means of some small gears. They in-turn rotate the pointer to indicate the system pressure on a calibrated scale. The temperature part of the gauge also utilises a Bourdon tube. It has a sealed capillary tube filled with a temperature sensitive liquid that produces a proportional vapour pressure on the Bourdon tube. As the temperature changes, the pressure inside the Bourdon tube changes, which in turn moves the pointer on the gauge. The gauges are available with either a back or bottom ½” BSP connection depending on the installation.