Pressure measurement and turbomachinery have been intimately linked since f
low field diagnosis was employed in verifying the operation of the first ga
s turbines. In the early years, time-mean pressures were required and exten
sive use of pneumatic connections between the measurement points and pressu
re transducers was made. Over the last two decades or so there has been a r
equirement to measure time-varying pressures in turbomachinery applications
to bandwidths of order 100 kHz and the silicon piezoresistive pressure sen
sor has been the device which has been at the heart of many of the measurem
ents. Although we mention other new developments in technology that are und
er way, this paper concentrates on the silicon piezoresistive sensor. The o
peration of the device in the context of gas turbine applications is outlin
ed and some of the special issues which arise and must be addressed for acc
urate measurements are discussed. Following this, two example fields of the
application of piezoresistive sensors are discussed in some detail, namely
, rotating blade static pressure measurements and fast response aerodynamic
probes. In both these cases instrumentation design considerations are disc
ussed, technological implementation details given and sample data displayed
and briefly discussed. Contemporary work elsewhere is included in the disc
ussion. Finally, conclusions are drawn and the future context for the piezo
resistive device is outlined.