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 ISO 7185 standard compilers were used, ending with the SVS Pascal compiler, a 32 bit DPMI extender based implementation. By 1993, ISO 7185 compatible compilers that delivered high quality 32 bit code were dying off. At this point, the choice was to stop using Pascal, or to revive the former IP Pascal project and modernize it as an 80386 compiler. At this point, a Pascal parser, and assembler (for Z80) were all that existed which were usable on the IBM-PC. From 1993 to 1994, the assembler was made modular to target multiple CPUs including the 80386, a linker to replace