Which type of charging method is NOT considered an active charged media type?

Non-contact charging is not classified as an active charged media type because it does not involve direct interaction or engagement between the charged medium and the particles being charged. Instead, non-contact charging relies on various techniques such as electric fields to influence the movement of charge carriers in the vicinity. This method does not actively impart charge to the particles in the same way that other methods do.

In contrast, triboelectric charging, corona charging, and charging by induction all involve mechanisms that directly engage the particles, allowing for an active transfer or manipulation of charge. For instance, triboelectric charging occurs through friction, where materials become charged by contact; corona charging employs ionization of air to create charged ions that can attach to particles; and charging by induction involves a nearby charge creating a separation of charge within a neutral object, which can then be influenced.

Understanding the distinctions between these charging methods is crucial, particularly in applications involving air filtration, where the method of charge can affect the efficiency of the filtration process.