  Atmospheric parameters and helium abundances of 44 bright subdwarf B stars
have been determined. More than half of our sample consists of newly discovered
stars from the Edinburgh Cape survey. We showed that effective temperatures and
surface gravities can be derived from high resolution echelle spectra with
sufficient accuracy. Systematic uncertainties have been determined by comparing
the parameters derived from the high resolution data with the ones derived from
medium resolution spectra. Helium abundances have been measured with high
accuracy. Besides the known correlation of helium abundance with temperature,
two distinct sequences in helium abundance have been confirmed. Significant
isotopic shifts of helium lines due to an enrichment in $^{3}$He have been
found in the spectra of 8 sdBs. Most of these stars cluster in a small
temperature range between $27\,000\,{\rm K}$ and $31\,000\,{\rm K}$ very
similar to the known $^{3}$He-rich main sequence B stars, which also cluster in
such a small strip, but at different temperatures. Both the helium sequences
and the isotopic anomaly are discussed.
