Distinguish dry appearance from cleanliness

Compare sheltered recesses, upward-facing ledges and open rain-washed surfaces. A pale deposit may be salt or another material, so identification should be based on evidence rather than colour. ASSDA discusses how salts and humidity interact in surface exposure. That supports considering retained contamination but does not establish a universal humidity threshold or prove the chemistry of a particular turbine deposit.

Choose relevant contamination evidence

If the deposit affects a repair or protection decision, a qualified assessor can determine whether a surface-extraction test or other sampling is appropriate. Such a result represents the sampled location and method; it does not automatically characterize hidden joints or every surface of the turbine. A conductivity-based result concerns soluble contamination and should not be presented as an exact identification of all species without further analysis.

A freshly rain-washed open face and an apparently dry sheltered recess can carry different residual contamination. Sampling the easier open face should not be used to declare the recess clean unless the assessment can justify why that location represents the unresolved exposure.

Connect the result to a specific action

The next question is whether the identified surface needs approved cleaning, protection assessment or investigation of recurring deposition. A current dry state does not resolve a future wetting mechanism, while a positive contamination result alone does not establish material loss. MARSTON salt tolerance, protective finish and maintenance intervals are unconfirmed here. Any response must account for the actual material, component function and applicable instructions.