Table 2.

Summarized results for PTB luminous intensity transfer lamps measured at NIST and PTB with average differences between the values

Lamp no. lamp current dist. temp.	Date 1993	Lamp voltage V		Luminous intensity I cd		Difference	Burning time min
		NIST	PTB	NIST	PTB	(NIST–PTB)/PTB
260S	March		27.847		196.22		40
5.500 A	May	27.851		196.65			60
2740 K	October	27.850		196.39			60
	October		27.845		196.06		40
	Average	27.851	27.846	196.52	196.14	0.19 %	Total 200
	Δa	0.00%	0.01 %	0.13 %	0.08 %
264S	March		27.953		198.64		80
5.500 A	May	27.956		199.09			60
2750 K	October	27.957		198.64			60
	October		27.950		198.43		40
	Average	27.957	27.952	198.86	198.54	0.16 %	Total 240
	Δ	0.00%	0.01 %	0.23 %	0.11 %
Ulabb				0.21 %	0.10 %
Difference of luminous intensity values measured by NIST and by PTB: + 0.18 % ± 0.24 %(U)

^aΔ is the difference of the two measurements of each lamp at each laboratory, [I(first)-I(second)]/I(first).

^bU_lab is two times the standard deviation of luminous intensity values of each laboratory normalized by the average of each lamp. U is the quadrature sum of U_lab(NIST) and U_lab(PTB).