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
IP Pascal coupled to output into a graphical window. Example: "hello world" with graphical commands added. Note that standard Pascal output statements are still used. Because IP Pascal modules can "override" each other, a graphical extension module (or any other type of module) can override the standard I/O calls implemented in a module below it. Thus, paslib implements standard Pascal statements such as read, write, and other support services. gralib overrides these services and redirects all standard Pascal I/O to graphical windows. The difference between this and such libraries in other implementations is that you typically have to stop using the standard