Champion Aerospace CT-482 – Spark Plug Erosion Gauge

The Champion Aerospace CT-482 Spark Plug Erosion Gauge provides an easy, accurate method of determining whether your aircraft spark plugs have reached their maximum wear limit. Simply re-gap the used plug to .016" nominal, then attempt to insert the electrode assembly through the chamfered hole in the gauge. If the electrode assembly penetrates the hole, this indicates that the spark plug has exceeded its recommended wear limits and should be replaced.

The CT-482 Spark Plug Erosion Gauge is calibrated to reject plugs after their electrodes have eroded to at least one-half of their original thickness. Although aviation spark plugs will continue to fire past this wear point, the rate of electrode erosion will increase as a result of non-parallel gaps and reduced sparking area. This leads to intermittent misfires, increased ignition system wear, and possibly costly unscheduled maintenance.

Let this convenient tool be your guide for deciding whether to reinstall used spark plugs – if the plug fails the CT-482 test, it's time to scrap it!