This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging and storage requirements of general pressure gauges. This standard applies to mechanical pointer pressure gauges, vacuum gauges and pressure vacuum gauges (hereinafter referred to as instruments) such as spring tubes (C-shaped tubes, coiled tubes, and spiral tubes). This standard does not apply to instruments with additional devices and special functions. For the additional requirements for instruments measuring special media such as hydrogen and oxygen, see the provisions in Appendix A of this standard.