6-16
STANDARD TUBE
t0 = 1 SECOND
t0 = 60 SECONDS*
OPTION 004 TUBE
t0 = 1 SECOND
SYSTEM BW = 100 kHz
sy(t)
10-9
10-10
10-11
10-12
10-13
10-14
10-15
10-16
10-3
10-2
10-1
100
101
102
103
104
105
106
AVERAGING TIME t (SECONDS)
* The 60 s time constant
provides better short-
term stability, but it is
usable only in benign
environments.
Short-Term Stability of a Cs Standard