Results

Using the parameters used previously, and C_eff = 0.5, $\eta$ = 0.6, and Trec = 100 K, we can make the following comparison of the variations of Tcal

Item	Tcab	Trec	Feff	Ceff	$\eta$
Typical Error	2 K	10 K	0.01	0.02	0.02
Induced variation (in %)	0.7	0.3	1.3	2.0	-0.5

This shows that the maximum effect is from C_eff if this method is used, from F_eff otherwise. It also indicates that the ``reduced chopper'' calibration is not a good technique, but a switchable attenuator should be used instead.