These differential pressure gauges are suitable for measuring of liquid and gaseous media, although this may not be to viscous or be susceptible to crystallization.
The two independently indicating Bourdon tube measuring systems work in a steel case.
Both pointers turn around the same axle and give + and - pressure separately.
The pointer of the low-pressure side has the form of a dial. On this dial the pressure difference between the low and high pressure side is given which may not exceed 50% of the full measuring range.