Quartzdyne downhole pressure transducers are designed to respond to very rapid changes in pressure. The problem to be solved by the transducer engineer is that large, rapid changes in pressure produce temperature changes (due the work required to compress fluids), this is commonly called "PV heating".
Although the pressure sensor responds instantaneously to pressure, it cannot respond instantaneously to temperature. It does have some thermal mass. Quartzdyne includes both pressure and temperature sensors inside the transducer; matching the response of these sensors to both pressure and temperature events provides the rapid response to pressure steps and temperature ramps.
Quartzdyne has designed the transducers for optimum performance in the downhole environment of simultaneously increasing pressure and temperature. Experimental results showing the response to extreme conditions are demonstrated in a tech note.