As discussed above in section 5.2, the integration ramps can be either
0.5 or 0.25 seconds long. For bright sources (i.e. more than 
Jy
at 120 micron), the 0.25 second ramps should be used in grating mode.
For all other sources 0.5 second ramps should be used. In FP mode this limit
is much higher, and will never be reached.
The effective length of each integration ramp is shorter than the
true ramp length (0.5 or 0.25 seconds), because the first 0.1 seconds
of each integration ramp is discarded for technical reasons. Therefore
for 0.5 second ramps 0.4 seconds is effectively used, for 0.25 second
ramps only 0.15 seconds is effectively used.