The mini-photohelic differential pressure gauge/switch combines a differential pressure gauge with two SPDT switch set points. It is designed to measure and control positive, negative or differential pressures consisting of non-combustible and non-corrosive gases. The gauge reading is independent of the switch operation. The switching status is visible by LED indicators located on the front and rear of the gauge. The set points are adjusted with pushbuttons on the back of the unit. This extremely compact switch/gauge is ideal for fume hoods, dust collection, pneumatic conveying and clean room applications.