PEEK plastic pitot probes are valued for their corrosion resistance in high-humidity environments (95%RH), but effective moisture-proof sealing is critical to prevent internal damage and measurement drift.Gas Pressure Scanwelcome to click on the website to learn more!
The primary sealing challenge is protecting the probe’s internal pressure channels and electronics (if integrated) from condensation. A dual-seal system—combining a silicone O-ring (70 Shore A hardness) with high-temperature epoxy adhesive—proves most effective. The O-ring compresses between the probe head and stem to block surface moisture, while the epoxy fills micro-gaps in the joint, preventing capillary water ingress. In a tropical climate test, a PEEK probe with this setup maintained calibration for 6 months, whereas one with only an O-ring showed 2% pressure drift after 2 months due to moisture seepage.
Probe hole design also aids moisture resistance. Tapered holes (0.5mm at the tip, 1mm internally) reduce water retention compared to straight holes, as observed in a fog chamber test where tapered holes dried 30% faster after exposure. Adding a hydrophobic coating (e.g., PTFE) to the hole interior further minimizes water adhesion, though the coating must be thin (<5μm) to avoid altering hole dimensions.
Electrical components (e.g., pressure transducers in integrated probes) require additional protection, such as potting with polyurethane resin. In a 95%RH warehouse airflow test, an unprotected transducer failed after 3 weeks, while a potted one functioned for over a year.
Installation in high humidity should include mounting the probe with a slight downward angle (5-10°) to allow condensation to drain, rather than pooling at the head. Regular inspection of seals—looking for O-ring cracking or adhesive degradation—prevents sudden failures, with replacement recommended every 12-18 months in continuous high-humidity use.