  In this work we describe some recent results concerning the application of
Resistive Plate Chambers operated in avalanche mode at atmospheric pressure for
high-resolution time-of-flight measurements. A combination of multiple,
mechanically accurate, thin gas gaps and state-of-the-art electronics yielded
an overall (detector plus electronics) timing accuracy better than 50 ps sigma
with a detection efficiency up to 99% for MIPs. Single gap chambers were also
tested in order to clarify experimentally several aspects of the mode of
operation of these detectors. These results open perspectives of affordable and
reliable high granularity large area TOF detectors, with an efficiency and time
resolution comparable to the existing scintillator-based TOF technology but
with a significantly, up to an order of magnitude, lower price per channel.
