The method
Before using the result
- Samples must represent equal-area cells and consistent velocity direction. Sampling location, instrument calibration and nonuniform-flow errors are not corrected.
Worked examples
These original training examples illustrate the method for IKECA Certified Exhaust Systems Inspector (CESI) Examination. Use the matching “Load example” button above to explore a variation; example values are not equipment settings or prescribed criteria.
1. Worked example
Convert equal-area velocity samples into a mean velocity and duct flow. Check the measurement pattern before treating an arithmetic mean as representative.
- Actual duct cross-sectional area
- 0.2 m²
Supplied equal-area traverse readings
| Velocity (m/s) |
|---|
| 4 |
| 5 |
| 6 |
| 5 |
- Mean = 20 / 4 = 5 m/s.
- Q = 0.2 × 5 m³/s.
- Mean velocity: 5 m/s
- Volume flow: 1 m³/s
2. Comparison example
Compare a different supplied condition using the same method. For Kitchen Exhaust Exam, the important check is that the input meaning, units and method assumptions still match the problem.
- Actual duct cross-sectional area
- 0.3 m²
Supplied equal-area traverse readings
| Velocity (m/s) |
|---|
| 4 |
| 5 |
| 6 |
| 5 |
- Mean = 20 / 4 = 5 m/s.
- Q = 0.3 × 5 m³/s.
- Mean velocity: 5 m/s
- Volume flow: 1.5 m³/s
Check your understanding
1. Which relationship is used?
For equal-area sampling cells: mean velocity = Σvi/n; volume flow = area × mean velocity.
2. Which assumption should you check first?
Samples must represent equal-area cells and consistent velocity direction. Sampling location, instrument calibration and nonuniform-flow errors are not corrected.
3. How should you verify a different unit system?
Convert every input to the displayed calculation units first. Equivalent physical inputs must give equivalent results; a unit label alone does not convert a number.
Continue with the matching exam topic
This tool connects to IKECA Certified Exhaust Systems Inspector (CESI) Examination free practice. Work through a question independently, then use the calculation steps to identify where your method differs. The tool stays free whether or not you choose paid preparation.