The core of selection is "需求排序 (demand ranking)"; blindly pursuing multi-parameter measurement often leads to cost escalation and insufficient accuracy.Gas Pressure Scanwelcome to click on the website to learn more!
Logic for Parameter Priority Judgment:
1. Pressure Measurement (total pressure/static pressure):
- For obtaining flow field pressure distribution (e.g., pipeline pressure drop, wind tunnel wall pressure), prioritize "total pressure + static pressure integrated probes" (e.g., 3-hole/5-hole combined designs);
- Note: Static pressure measurement has strict requirements for probe surface roughness (Ra ≤0.8μm). In a chemical pipeline test, surface roughness caused a 4% static pressure error.
2. Velocity Measurement:
- Subsonic (Ma <0.8) can use ordinary velocity probes; supersonic (Ma >1.2) requires dedicated supersonic probes (with oblique shock cones on the head);
- Velocity accuracy is related to probe response time (dynamic flow fields require <10ms response, static flow fields can relax to 50ms).
3. Temperature Measurement:
- Only select "pitot probe + thermocouple" composite models when simultaneous total temperature acquisition is needed (e.g., certain aero-engine tests requiring simultaneous total pressure and total temperature measurement);
- Note: The temperature sensor must be ≥5mm from the pressure-measuring hole to avoid thermal disturbance affecting pressure measurement (excessively close spacing once caused 2% fluctuations in pressure data).
Decision Example:
In "vehicle surface flow field testing" in an automotive wind tunnel, the priority was "pressure distribution > velocity magnitude > temperature", and a 5-hole static pressure-priority probe was ultimately selected (cost reduced by 30%, meeting test requirements).