Pressure measurement because atmospheric pressure is always changing and the reference in this case is fixed at 1 bar. To produce an absolute pressure sensor, the manufacturer seals a high vacuum behind the sensing diaphragm. If the process-pressure connection of an absolute-pressure transmitter is open to the air, it will read the actual barometric pressure. The SI unit for pressure is the pascal (Pa), equal to one newton per square metre (N·m or kg·m·s). This special name for the unit was added in 1971; before that, pressure in SI was expressed in units such as N·m. When indicated, the zero reference is
PA-DSS aggressive push into such technology (chip and pin) in August 2011. The PCI SSC has published additional materials that further clarify PA-DSS, including the following: PA-DSS The Payment Application Data Security Standard (PA-DSS), formerly referred to as the Payment Application Best Practices (PABP), is the global security standard created by the Payment Card Industry Security Standards Council (PCI SSC). PA-DSS was implemented in an effort to provide the definitive data standard for software vendors that develop payment applications. The standard aims to prevent developed payment applications for third parties from storing prohibited secure data including magnetic stripe, CVV2, or PIN.