A flow meter including at least one flow valve used to performance test system compressors is described. The method for contextual adaptive advertising comprises tracking user behavior across multiple modalities or devices, storing one or more representations of user behavior in a log as descriptors, normalizing the descriptors, merging the normalized descriptors into a unified click or interactive stream, and generating a behavioral model by analyzing the click or interactive stream. The interchangeable socket module is exposed to the exterior via an opening defined by the outer panel for easy maintenance accessibility. The present invention also suppresses a dialog box when a request for a certain file type is made by a hosted browser.