Pascals (Pa)

The pascal (Pa) is the SI derived unit of pressure, defined as one newton per square meter (1 Pa = 1 N/m²). It quantifies force applied evenly over an area and is expressed as kg·m⁻¹·s⁻² in base SI units [bipm-si-brochure].

Origin

Named after Blaise Pascal, the pascal was adopted by BIPM in 1971 to replace older pressure units and standardize measurement in the SI system. It reflects the link between force and area in pressure measurements [bipm-si-brochure].

Worldwide Use

Pascals are the standard pressure unit in scientific research, meteorology, and engineering globally. Countries following SI, including members of ISO and NIST guidelines, use pascals for atmospheric and mechanical pressure [nist-si-guide].

Common References

  • Standard atmospheric pressure is 101,325 Pa
  • Tire inflation pressures range from 200,000 to 300,000 Pa
  • Human blood pressure is about 16,000 Pa (120 mmHg)
  • Vacuum chambers operate below 1,000 Pa
  • Building codes specify pressure resistance in pascals