Temperature change Delta T of a pyroelectric sample can lead to a high elec
tric field strength E-gamma/Delta T = 1 MV/Km. When the pyroelectric field
E-gamma exceeds the breakdown strength E-t of the surrounding gas an extern
al pyroelectric breakdown occurs. Current pulses accompany the breakdown; t
he pulse amplitude and their repetition are determined by the value of the
pyroelectric charge and by the time of its accumulation. The conditions of
external pyroelectric breakdown are discussed and pyroelectric sensors usin
g LiNbO3 and LATGS samples, cut perpendicularly to the polar axis, are desc
ribed. Sensors provided with optical, acoustical or electrical channels can
be used for temperature stabilization control or fire protection systems.