A pressure gauge is a manometer whose function is in principle to measure negative pressures up to pressures of 2500 bar or more. There are 3 types of pressure, the absolute, the relative and the differential. This product is used to measure the pressure of gases (compressed air, natural gas, nitrogen, etc.) and liquids (water, hydrocarbon oils, milk, etc.). The pressure gauge is used to measure pressure, vacuum or differential pressure. It can be used in liquid or aerial form. Unlike an industrial needle gauge whose accuracy can not exceed 0.1%. The digital manometer is often used as a reference instrument with a measurement accuracy of up to 0.02%, which is 5 times more accurate than the most accurate mechanical manometers. These tests generate individual data and store them in the meter to characterize its performance in this temperature range.