What is the double needle and double tube pressure gauge for

The double needle Bai pressure gauge is mainly used to measure the pressure in the hydraulic Du system or air cylinder of rolling stock. It can also measure two identical or different pressures which are not corrosive to copper alloy Dao and tin lead alloy fiber, non crystalline and non solidification media.
The instrument consists of two sets of independent measuring system and indicating device.
The working principle of the instrument is based on the elastic deformation of the elastic element (the spring tube in the measuring system). In other words, under the pressure of the measured medium, the ends of the two spring tubes are driven respectively to produce corresponding displacement. With the help of the pull rod through the gear transmission mechanism and amplified, the red and black pointer on the fixed gear shaft will respectively indicate the two measured values on the disc degree.