(Rotax oil pressure sensor: last updated by Gabriel on October 12, 2022)
For the EMS design, it was necessary to experimentally characterize the VDO resistive oil pressure sensors (Rotax part #956355-first generation and #956357-second generation), which are still mounted on most Rotax 912x engines (fig. 1). The manufacturer does not provide resistance curves as a function of pressure, so they had to be established. This article does not apply to 3rd generation (Honeywell ref. 956413) and 4th generation (Keller 456180) electronic sensors fitted to newer engines.
While waiting for a complete article detailing the methodology, below are the resistance curves as a function of pressure, obtained for three 1st or 2nd generation sensors, one having been used for approximately 800 hours (gray curve), and the other two were new (red and blue curves). The Excel spreadsheet provides the trendline equation used in the EMS software.
