As you people already know, pressure is defined as the force acting per unit square metre area. Pressure measurement is very important and crucial parameter of any process. There are various types of units like Kg/cm2, Bar, N/m2, mmHg, mmWc, Psi, Pascal. The majorly used units in industries are Kg/cm2 and Bar for high pressure applications. Others units like mmHg, mmWc, Psi, Pascal are used for low pressure applications and mostly in calibration labs.
Pressure is globally addressed with 3 categories termed as “Atmospheric pressure”, “Gauge pressure” and “Absolute pressure”.
Atmospheric pressure, as the name suggests, is the pressure available in our atmosphere naturally. It is the pressure in our environment in which we live and do our day to day activities. This pressure acts on everything which is exposed & open to atmosphere.
Gauge pressure is simply the pressure of the fluid (fluid means anything that flows like air, gas, water, liquid etc.) in a closed system for e.g. the blood pressure inside human body, water pressure inside a pipe line, Rice or Dal pressure inside a pressure cooker, gas pressure inside a LPG cylinder, water pressure inside a water bottle, fluid pressure inside a container/vessel/tank and so on. Hope you can imagine now these examples which are very common and are frequently seen in our day to day life.
Absolute pressure is the mathematical representation; used for getting results in calculations, which are not possible by using only Atmospheric pressure values or Gauge pressure values, as in some cases the calculation results tend towards infinity and thus no definite results are achieved. Thus, in those cases absolute pressure values are used which are simply addition of values of Gauge pressure and Atmospheric pressure. By doing this, all the mathematical calculations using absolute values lead to definite results rather than tending towards infinity and thus avoiding indefinite results.
Pressure parameter is very important to know for an Instrumentation Engineer as the same is highly encountered in all the applications, projects and work profiles. The importance of pressure and its measurement has been developed a lot in last 20 years. However, instengg.com is here to help you in guiding and making you aware about all those pressure measurements with respect to instrumentation approach.
