A description is presented of an upgraded trap-detector-based realization o
f the units of luminous intensity (candela) and illuminance (lux) at the He
lsinki University of Technology (HUT). The realization is accomplished usin
g a reference photometer, a light source and a distance-measurement system.
A thorough characterization is presented of the reference photometer, cons
isting of a reflection trap detector, a temperature-controlled V(lambda) fi
lter and a high-precision aperture. The maintenance of the units is describ
ed. An updated uncertainty budget of the realization is given. Two of the t
hree main uncertainty components of our earlier realizations have been sign
ificantly decreased. The uncertainty analysis indicates a relative expanded
uncertainty(1) of 2.2 x 10(-3) for the realization of the candela and 1.8
x 10(-3) for that of the lux. The HUT has participated in three internation
al measurement comparisons, whose results are reviewed. According to the re
sults, the HUT candela deviates by +4.0 x 10(-3) from the candela of the Sw
edish National Testing and Research Institute with an expanded uncertainty
of 10(-2), -2.7 x 10(-3) from that of the National Physical Laboratory (UK)
with an expanded uncertainty of 5.6 x 10(-3), and -3.3 x 10(-3) from the w
orld mean with an expanded uncertainty of 5.9 x 10(-3).