The authors examine the influence of the light-shift effect on the fre
quency stability of a laser-pumped Rb gas cell standard for averaging
time up to 10(4)s. The measured stability at the flicker floor is 7 x
10(-14) for averaging times from 200 to 5000s, providing that the lase
r frequency is properly set at the optical resonance frequency, and co
rrecting for the variation of atmospheric pressure.