Fecha de publicación: 05/07/1949 Fuente: WIPO "honey" 625,826. Testing ignition. HONEY, A. Feb. 2, 1948, No. 20810/46. [Class 7 (iv)] The invention relates to a testing device for the sparking plugs of internal combustion engines of the kind wherein relatively moveable electrodes form a calibrated spark gap and are connected to conductors which can be applied to the poles of the sparking plug the electrodes being housed within a substantially cylindrical casing, one being fixed therein and the other moveable relatively thereto and tapered at its end, the distance apart of the electrodes being indicated on a suitable scale provided longitudinally on the casing. When the terminals b1, b2 are connected in parallel with the sparking plug to be tested, the insulated stem a1 of a moving electrode a2 is screwed upwardly in an insulted casing g1 until the gap between the electrode a2 and a fixed electrode c1 is of such a length as to permit the formation of a spark. The casing g1 may be made partly transparent or with an opening or transparent window to enable the spark to be seen. The insulating stem a1 is provided with a peripheral mark a6 which co-operates with a scale on the casing g1, that is calibrated in volts or thousanths of an inch ; an insulated screw m1 enables the two electrodes a2, c1 to be brought into contact in order to effect zero adjustment on the scale.