Flowmeters measure the shielding gas flow rate in CFH or L/min. Which option below reflects this?

• A. BTU per second
• B. PSI
• C. CFH or L/min
• D. kPa

Answer: (C)

Flow meters quantify how much shielding gas passes to the weld per unit time, which is a volumetric flow rate. This is why the readout uses units like cubic feet per hour (CFH) or liters per minute (L/min). Shielding gas must flow continually to protect the weld pool, so listing volume per time makes the measurement meaningful for the welding process. The other quantities shown are different: BTU per second is an energy rate, while PSI and kPa are pressure measurements. Pressure indicates the force per area, not how much gas is moving, so they don’t reflect the flow rate. Therefore, CFH or L/min is the correct way to express the shielding gas flow rate.