wavel.(air)	wavel.(vacuum)	cross sect.	uncertainty

243.998		244.062		9.48e-18	6.0e-20
248.249		248.323		1.044e-17	7.0e-20
253.65		253.73		1.127e-17	9.7e-20
257.260		257.337		1.107e-17	7.0e-20