An arrangement is provided for measuring jitter between an initiating network end point and a receiving network end point. The computation circuitry is to monitor a sensor signal of a sensor of the sensor cartridge, detect a leak based on the sensor signal, and control fluid flow of the fluidic subsystem in response to detecting. The immobilized complexing agents on the brush can effectively pick up metal ions or metal oxides from the substrate surface upon contact but may not etch into the metal lines.