The amount of dirt collected by a filter when the pressure reaches a predetermined point is called the ______.

• A. Dirt holding capacity
• B. Filtration capacity
• C. Contamination capacity
• D. Dirt retention

Answer: (A)

As a filter collects dirt, the pressure across it climbs until it hits a preset limit. The total amount of dirt the filter can hold up to that limit is called its dirt holding capacity. This concept helps determine when the filter should be replaced to prevent excessive pressure drop and loss of flow. Other terms like filtration capacity describe how well the filter removes contaminants in general, not how much dirt it can accumulate before reaching the pressure threshold; dirt retention and contamination capacity aren’t the standard terms used for this specific measure.