Pitot Traverse Method: obtained average velocity pressure by measuring at points in a number equal to what?

Pitot Traverse Method: obtained average velocity pressure by measuring at points in a number equal to what?

• A. The area cross section
• B. The duct diameter
• C. The height of the duct
• D. The number of points in the duct

Answer: (A)

The key idea behind the Pitot traverse is to get a representative average by sampling the flow across the entire duct cross-section, not just at a single point. Velocity in duct flows isn’t uniform; it varies from the center to the walls due to friction and boundary layers. To approximate the true average velocity, you take multiple readings across the cross-section. The guideline given here is to use a number of measurement locations that matches the cross-sectional area: larger ducts need more sampling points to cover the area adequately and capture the velocity variations. Once you have each point’s velocity (from the Pitot pressure at that point), you average them to obtain the average velocity across the section, which then yields the average velocity pressure. The other options don’t describe this sampling rule: the diameter or height isn’t the rule for how many points, and “the number of points in the duct” is not a guiding principle for how many you should take.

The key idea behind the Pitot traverse is to get a representative average by sampling the flow across the entire duct cross-section, not just at a single point. Velocity in duct flows isn’t uniform; it varies from the center to the walls due to friction and boundary layers. To approximate the true average velocity, you take multiple readings across the cross-section. The guideline given here is to use a number of measurement locations that matches the cross-sectional area: larger ducts need more sampling points to cover the area adequately and capture the velocity variations. Once you have each point’s velocity (from the Pitot pressure at that point), you average them to obtain the average velocity across the section, which then yields the average velocity pressure.

The other options don’t describe this sampling rule: the diameter or height isn’t the rule for how many points, and “the number of points in the duct” is not a guiding principle for how many you should take.