A radiation-pressure-ceiling scan raises irradiance or reflection factor across three rows, checking when pressure reaches the stated ceiling for the surface. The arithmetic is exact only for the stated irradiance, pressure factors, ceiling values, and rows in the ideal uniform-beam, flat-surface model. Real measurements add beam profile, alignment, reflectivity/absorption, detector calibration, timing/area calibration, surface geometry, finite precision, and uncertainty.
Irradiance and mode are scanned through a pressure ceiling. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Radiation pressure is scanned against a pressure ceiling
The training speed is fixed at 6 m/s and the mode is absorber. The source irradiance 3 watts per square meter gives pressure 1 over 2 Pa which is below the 1 Pa ceiling.
p=mI/c=1⋅3/6=21Pa
Radiation pressure is scanned against a pressure ceiling
The training speed is fixed at 6 m/s and the mode is absorber. The source irradiance 6 watts per square meter gives pressure 1 Pa which is at the 1 Pa ceiling.
p=mI/c=1⋅6/6=1Pa
Radiation pressure is scanned against a pressure ceiling
The training speed is fixed at 6 m/s and the mode is mirror. The source irradiance 6 watts per square meter gives pressure 2 Pa which is above the 1 Pa ceiling.