Signal Waveform Generator Performance Test

PDFTech ReportDOT-VNTSC-NHTSA-91-1HS-807 768HS176/S1007AccuracyCollisionsData collectionElectromagnetic wave propagationFrequency responseImpact testsPerformance evaluationsSignal generatorsTestingUnited StatesUnited States. National Highway Traffic Safety AdministrationNickles, John E.John A. Volpe National Transportation Systems Center, (U.S.)United States. National Highway Traffic Safety AdministrationNTL-SAFETY AND SECURITY-Highway SafetyNTL-SAFETY AND SECURITY-Vehicle DesignNTL-SAFETY AND SECURITY-SAFETY AND SECURITYVolpe National Transportation Systems Center, Technical Reference CenterA signal waveform generator (SWG) was tested to determine its suitability for use in testing crash test data acquisition systems. The outputs of the SWG were recorded by a precise, high speed data acquisitions card plugged into the option card slot of an IBM PC compatible desk top computer. The recorded data were analyzed using a modified version of the software that was developed for analyzing recorded SWG outputs when testing crash test data acquisition systems. For measuring small time differences between waveform leading edges, a digital storage oscilloscope was used. SWG time base accuracy meets the requirements of SAE J211. When the SWG is operated at the high output voltage level, the measured amplitude accuracy is plus or minus 0.06% of full scale. But when the SWG is operated at the low output voltage level, the measured amplitude accuracy degrades to plus or minus 0.31% of full scale. A large part of this accuracy degradation is caused by a measured offset of the waveform zero level from the calibration zero level. The frequency response of the SWG meets the requirements implied by SAE J211. The measured performance of the SWG is sufficiently precise that the use of the SWG for testing crash test data acquisition systems will be satisfactory