Carbon fiber reinforced polymer (CFRP) pitot probes are valued for their high tensile strength and lightweight properties, but their temperature limitations require careful consideration in flow measurement applications.Gas Pressure Scanwelcome to click on the website to learn more!
CFRP’s tensile strength (typically 1500-2000 MPa) is 3-4 times that of 304 stainless steel, allowing for thin-walled designs that minimize airflow disturbance. In a drone aerodynamic test, a 2mm diameter CFRP probe withstood 500 N of tensile force without deformation, whereas a stainless steel probe of the same size bent at 300 N. This strength-to-weight advantage makes CFRP ideal for weight-sensitive applications like small aircraft models.
However, CFRP’s temperature resistance is limited to 200°C for standard epoxy matrices. Above this temperature, the polymer matrix begins to soften, reducing structural integrity and causing probe deflection. A laboratory test at 250°C showed a 10% loss in tensile strength after 100 hours, leading to 3% measurement error due to probe misalignment. High-temperature matrices like polyimide extend this limit to 300°C but increase cost by 50%.
Moisture absorption is another concern. CFRP absorbs 0.5-1% of its weight in water over time, which can swell the material and alter hole dimensions. In a high-humidity wind tunnel test, an uncoated CFRP probe showed 2% pressure drift after 6 months, while a epoxy-coated one remained stable.
For applications below 200°C—such as automotive wind tunnels, HVAC systems, or UAV testing—CFRP probes offer superior performance. Beyond this range, metal or ceramic probes are necessary to avoid thermal degradation.