Which letter represents the variable of pressure in instrumentation?

In instrumentation, the letter that represents pressure is commonly denoted by "P." This convention is widely accepted in scientific and engineering fields, where various physical quantities are represented by specific letters to maintain clarity and consistency in communication. For instance, "T" typically represents temperature, "S" might denote a variable such as entropy or entropy flow, and "L" can refer to length or level in specific contexts. Therefore, the choice of "P" for pressure aligns seamlessly with standard notations used throughout various disciplines in engineering and instrumentation. This clarity helps professionals interpret data and diagrams effectively, ensuring everyone has a common understanding of what each symbol represents.