IP22 is an enclosure protection rating. It describes specific test conditions for solid objects and falling water. It does not describe medical suitability, treatment effectiveness, or waterproofing.
Source boundary
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Practical meaning
Explain what the specification changes for the reader.
Publication check
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IP22 is an enclosure protection rating. It describes specific test conditions for solid objects and falling water. It does not describe medical suitability, treatment effectiveness, or waterproofing.
Some readers search for “IP 22 filter rating.” That is understandable device language, but “filter rating” is not the formal meaning of IP22. The useful question is how much exposure the controller can tolerate under the rating conditions.
What the first digit tells you
The first digit is 2. It indicates protection against solid objects 12.5 mm or larger. This is limited object protection. It is not a dust-tight rating.
What the second digit tells you
The second digit is also 2. It indicates protection against vertically falling water drops when the enclosure is tilted up to 15 degrees. It does not cover water jets, heavy splashing, showers, pools, or immersion.
How the rating changes everyday handling
Keep the controller, cable, and charging connection dry. Use the device in a dry, stable place. Keep it away from sinks, baths, rain, and wet floors.
IP22 does not make the ST-504 waterproof. Do not use the rating as permission to test the device in water. If liquid enters the controller, stop using it and contact support. Do not open the unit yourself.
For cleaning, follow the ST-504 cleaning and maintenance guide. Turn the device off. Let it cool. Use a soft, slightly damp sponge. Keep liquid out of the main unit.
What IP22 cannot answer
The rating cannot answer whether compression is suitable for a person. It cannot explain a new symptom. It cannot establish electrical safety in every environment. Use the ST-504 safety guide when the question involves symptoms, medical restrictions, or non-use.
For wider product context, see the ST-504 complete guide. The current instruction for use controls the exact cleaning and operating limits.
