The transient behavior of IT equipment can be represented by a lumped thermal capacitance for use in data center level transient thermal simulations. Previous work has proposed a mathematical methodology to extract the necessary lumped capacitance parameters, the server's time constant and heat transfer effectiveness, via air temperature measurements. This work describes and experimentally tests that proposed methodology to introduce a possible approach for developing an easy-to-use database of lumped capacitance characteristics for use in transient thermal simulations. The database will allow the user to select the appropriate transient parameters based on characteristics that do not require an "autopsy" of each-and-every server in the data center. Experiments are conducted to provide representative transient parameters which classify the servers by mass density and operating air flow rate. The paper describes the experimental methodology in detail to allow for the easy addition of other IT equipment or future server generations.