  We present a thermometry scheme to extract the temperature of a 2DEG by
monitoring the charge occupation of a weakly tunnel-coupled 'thermometer'
quantum dot using a quantum point contact detector. Electronic temperatures
between 97 mK and 307 mK are measured by this method with an accuracy of up to
3 mK, and agree with those obtained by measuring transport through a quantum
dot. The thermometer does not pass a current through the 2DEG, and can be
incorporated as an add-on to measure the temperature simultaneously with
another operating device. Further, the tuning is independent of temperature.
