Table 2.

Variability of Type 1 phantoms. Apart from the last column, which describes the inter-device variability, all the CVs reported are intra-device variabilities averaged over all the devices. See text for details.

Parameter	Phantom	${\mathit{CV}}_{\mathit{single}\mathit{acq}.}$	${\mathit{CV}}_{\mathit{replac}.}$	${\mathit{CV}}_{\mathit{hours}}$	${\mathit{CV}}_{\mathit{days}}$	${\mathit{CV}}_{\mathit{months}}$	${\mathit{CV}}_{\mathit{operator}}$	${\mathit{CV}}_{\mathit{device}}$
		(%)	(%)	(%)	(%)	(%)	(%)	(%)
TSI	PB300	0.08	0.08	0.8	1.1	0.8	0.09	2.5
TSI	PB312	0.09	0.2	0.3	1.3	1.2	0.5	3.8
THC	PB300	0.04	0.2	1.3	0.3	2.8	0.1	3.6
THC	PB312	0.04	0.3	0.09	0.9	2.1	0.2	4.5