Top interview questions on flow measurement

What are the types flow meters?

  • Orifice meter

  • Pilot tube

  • Rotameter

  • Electromagnetic flowmeter

  • Turbine type flowmeter

  • Vortex type flowmeter

What is Zero check and Static zero check on a DP flow transmitter?

Zero check : A procedure for checking the transmitter output is equal to 4mA, when it’s HP and LP chamber are equal and are at atmospheric pressure.

Static zero check: A procedure for checking the transmitter output is equal to 4mA, when it’s HP & LP chambers are at equal and are at the operating pressure.

What is the difference b/w volumetric and rate of flow?

Volumetric flow: The total amount of fluid passed through a process line. units: Barrel, cubic meter…

Rate of flow: The amount of fluid moving through a process line per period of time. units: Barrel per day, cubic meter per day…

What is the purpose of small holes above or below the orifice plate?

Small holes named weep holes are at the top for liquid flow stream to pass out small amount of the gas or vapor present in the liquid. Weep holes are at the bottom for gaseous stream to pass out any condensation and liquid present in the gas

How installation of DP flow transmitter on a gas and liquid pipe line differs?

For gas line, DP are installed above the orifice plate to avoid condensation of gas in the signal line and HP& LP champer.

For liquid line , DP are installed below the orifice plate to avoid gas trapping in the signal line and in the HP & LP line.