Areas of solid surfaces as small as 1 cm2were determined by krypton adsorption at liquid nitrogen temperature using an adsorption apparatus with a temperature‐compensated, differential tensimeter of symmetrical design. The BET monolayer volume of krypton for 50, 100, or 150 of 1 mm steel ball bearings was proportional to the number of balls used. The coefficient of proportionality agreed with the result on 10 000 ball bearings. The surface area of 50 ball bearings is to 1.57 cm2, which suggests that it is feasible to measure surface areas as small as 1 cm2. ©1995 American Institute of Physics.