This European standard defines requirements of pressure gauges for inflation of tyre and their testing in accordance with 86/217/EEC Directive. It establishes in the context of motor vehicles tyres, the minimum characteristics of the chain of measurement of mechanical apparatus intended to increase, inspect or adjust the pressure of tyres inflated by air or nitrogen. This apparatus classified in four different categories are hereinafter referred to by generic term, "pressure gauges". This chain of measurement consists of all the elements between the tyre valve and the display device (connector, hose, control device, measurement components, etc.). They indicate the pressure difference (Pe) between the air or the nitrogen in the tyre and the atmosphere. The field of application established above can be extended to other applications where no specific standard exists.