Date of Award


Document Type

Open Access Master's Report

Degree Name

Master of Science in Mechanical Engineering (MS)

Administrative Home Department

Department of Mechanical Engineering-Engineering Mechanics

Advisor 1

Jeffrey Naber

Committee Member 1

David Kubinski

Committee Member 2

Jason Blough


The radio frequency (RF) measurement technique has been shown to be a viable method for measurement of the amount of soot loaded onto DPF’s [1] and the amount of NH3 stored on SCR catalysts [2]. In one of the configurations, a microwave resonant cavity is formed by the metal can encasing the enclosed catalyst. Two metal probes acting as antennas are placed on either side of the catalyst. Power transmitted between the antennas is monitored as the frequency of the signal is swept. At certain frequencies, resonance is achieved. Measurements of the resonance frequencies, amplitude at resonance, and the mean amplitude over a frequency range give information regarding dielectric properties of the catalyst. We show how the RF response is influenced by soot and NH3 loading on the SDPF. We demonstrate the comparative responses and show how the soot loading can be determined with little influence by the stored NH3.