  We demonstrate experimentally that disorder enhanced Andreev current in a
tunnel junction between a normal metal and a superconductor provides a method
to measure electronic temperature, specifically at temperatures below 200 mK
when aluminium is used. This Andreev thermometer has some advantages over
conventional quasiparticle thermometers: for instance, it does not conduct heat
and its reading does not saturate until at lower temperatures. Another merit is
that the responsivity is constant over a wide temperature range.
