Side stream monitoring

A side stream monitoring device for a main unit such as a vessel, which effectively has the same geometrical and dynamic characteristics as those corresponding components in the vessel for enabling the side stream monitor to provide a ready indication and continuous monitor of the performance characteristics and quality of the corresponding components in the vessel, upon removal and testing or examination of the device. The apparatus and method for monitoring have particular utility in connection with clay filters or filter separators which are used for the removal of contaminants from, e.g. jet fuels. In each case a bypass side stream is disposed between the inlet and outlet lines of the filter or filter separator and located within the bypass line is a device which effectively is a reduced scale replica of a portion of the main unit which corresponds to the critical operating components thereof. For the clay filter a duplication of flow velocities and residence times of the fuel through a predetermined section of one of the main filter elements is reproduced. In the case of the filter separator, the side stream device comprises sections which are comprised of identical elements used in the main unit, including metal screens, fiber sheets, fiberglass screens, etc., except that each component of the side stream monitor is of a reduced size such that the ratio of the cross-sectional area to the liquid flow is the same as that which exists in the main unit for that particular component.