  The Burst and Transient Source Experiment (BATSE) on the Compton Gamma-Ray
Observatory has been shown to be sensitive to non-transient hard X-ray sources
in our galaxy, down to flux levels of 100 mCrab for daily measurements, 3 mCrab
for integrations over several years. We use the continuous BATSE database and
the Earth Occultation technique to extract average flux values between 20 and
200 keV from complete radio- and X-ray- selected BL Lac samples over a 2 year
period.
