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
Comparison of Object Pascal and C (if it has to be), i.e., its storage management is handled by the compiler (or more accurately, by the runtime code inserted by the compiler in the executable). String concatenation is done with the codice_65 operator, and string comparison can be done with standard relational operators (case sensitive): codice_66. Object Pascal also provides C-compatible strings under the type codice_67, with manipulation routines defined in the codice_68 unit. Moreover, Object Pascal provides a wide variety of string types: For convenience, the plain codice_76 type is provided, which, depending on a compiler switch, could mean codice_69, codice_71 or codice_74. An additional convention