Dimensionless quantity

Academic Freedom Index dissipation factor eccentricity relative density relative density logarithmic quantity coefficient of restitution chromatic number power efficiency crop factor dissipation factor apparent magnitude amount-of-substance fraction pressure coefficient magnitude of eclipse velocity factor natural number as dimensionless quantity angular measure relative biological effectiveness sphericity logarithmic decrement traffic intensity sun protection factor transmittance instructions per cycle void ratio thermal efficiency retardation factor aspect ratio mass ratio Air changes per hour Mahler volume absolute magnitude Mach number Hurst exponent volume ratio contrast sensitivity mixing ratio valence logarithmic unit refractive index drag coefficient net tonnage millesimal fineness salinity charge number number of particles packing density mathematical constant Poisson's ratio