Computational Fluid Dynamics (CFD) simulations are an important part of the development of new combustion strategies and innovative powertrain concepts. Since the ignition model initiates combustion in CFD simulation models of spark-ignited engines, it is crucial to have an ignition model that accurately represents the phenomena. Therefore, it is essential to have a fundamental physical understanding of ignition phenomena in order to optimise spark-ignited engines to meet customer expectations and regulatory requirements. This study presents new experimental/ measurement techniques developed with a focus on validating and improving existing ignition simulation models. These newly developed tests are used to observe sparks in an optically accessible flowbench capable of reproducing engine operating conditions. Through these tests, spark parameters such as spark elongation and phenomena such as the interaction of the spark with the surrounding medium have been observed and quantified. The knowledge gained was used to calibrate and improve an existing ignition simulation model.