  We have investigated one and two dimensional (1D and 2D) arrays of tunnel
junctions in partial Coulomb blockade regime. The absolute accuracy of the
Coulomb blockade thermometer is influenced by the external impedance of the
array, which is not the same in the different topologies of 1D and 2D arrays.
We demonstrate, both by experiment and by theoretical calculations in simple
geometries, that the 1D structures are better in this respect. Yet in both 1D
and 2D, the influence of the environment can be made arbitrarily small by
making the array sufficiently large.
