Flow Meters

Question 1

What is an orifice plate?

Answer 1

Used in flow meters

Question 2

What is Pressure Force of atmosphere at sea level?

Answer 2

14.7 lbs/square inch

Question 3

What Pressure Force is needed to create a Vacuum at sea level?

Answer 3

-14.7 lbs

Question 4

What is Turndown?

Answer 4

Also known as rangeability, is a ratio that measures the range of a device’s ability to accurately measure a quantity

Question 5

Equation for Turndown

Answer 5

Turndown Ratio - maximum flow / minimum flow

For Pressure Transmitters
The turndown ratio is the maximum pressure a device can measure divided by the minimum pressure it can accurately measure. For example, if a pressure transmitter has an upper range limit of 100 bar and a calibrated span of 10 bar, its turndown ratio is 10:1.

For Flow meters
The turndown ratio is the maximum flow a device can measure divided by the minimum flow it can accurately measure. For example, if a flow meter has a turndown ratio of 50:1, it can accurately measure down to 1/50th of the maximum flow.

Question 6

What is PSIG?

Answer 6

PSIG stands for pounds per square inch gauge

PSIG is a measurement of gauge pressure, which is the pressure above or below the local atmospheric pressure.

PSIG is always lower than PSIA (pounds per square inch absolute), which measures absolute pressure.

Question 7

What does PSIA stand for?

Answer 7

PSIA stands for “Pounds per Square Inch Absolute.” Absolute pressure is pressure relative to zero or absolute vacuum.

With atmospheric pressure added