GB/T 24622-2022 in English

Main revisions

Compared with GB/T24622-2009, the new standard mainly makes the following technical changes:

• Update the terminology system: replace the original "wettability" with "hydrophobicity", and replace "wettability grade (WC)" with "hydrophobicity grade (HC)"
• Delete the interfacial tension term and retain the precise definition of surface tension
• Adjust the aspect ratio requirement of the test sample in the spray method from 1:3 to 3:1
• Update the corresponding value of contact angle in the hydrophobicity grade judgment standard

Operation specification for contact angle method

Special attention should be paid:

1. Prioritize the measurement of rear contact angle θr (which can better reflect the true hydrophobicity)
2. The volume of the water droplet should be controlled at 5-50μL, and the volume can be appropriately increased for rough surfaces
3. The measurement should be completed within 1 minute after dripping
4. At least 6 data points at 3 different positions should be measured for each sample

Surface tension method safety warning

Method selection strategy

Recommendations based on application scenarios:

• New product development: Prefer the contact angle method to obtain accurate data
• Operation and maintenance: Combine the spray method (rapid screening) + surface tension method (key review)
• Contaminated areas: Avoid relying solely on the spray method, and combine it with laboratory analysis

Measurement report elements

The report must include:

1. Environmental parameters (temperature, humidity, wind speed)
2. Test product information (material, years of operation, pollution level)
3. Diagram of measurement location distribution
4. Description of abnormal data