Waterproof Watch Tester only one unit available A waterless type waterproof tester for watches. This tester uses positive pressure (external pressure) for checking the seal on watches. The watch is placed on the tester and a sensitive feeler gauge is set-up in contact with the watch crystal. The unit is sealed and the pressure in the unit is increased to from 2 to 10 bar. If the case is fully sealed, the external pressure will cause a deflection in the surface of the watch crystal. The feeler gauge detects this and registers it on the analogue scale. If this deflection holds steady the case is fully sealed. If the deflection subsides, then the watch has a pressure leak. If the deflection subsides quickly or there is no deflection then the leak is more serious. Dimensions: 115 x 280mm. Pressure is provided with a compressor. Compressor not included.