To provide a pressure detector that can be used normally for a long time by avoiding abnormalities in the sensitivity increase of a pressure-sensitive means.
Inspection pressure Pt is applied to the pressure-sensitive means 10, a generated pressure-sensitive signal Ss is processed by a processing section 12, strength Vd in the precessed pressure-sensitive processing signal Sd is detected by a pressure-sensitive determination means 14, and an amplification constant change signal Sc for changing an amplification constant at the processing section 12 is sent according to the change, thus preventing the strength in the pressure-sensitive processing signal Sd from changing. Optionally, a criterion value change signal Scr is sent to a determination section 13, and a reference value for determining pressure application is changed, thus making the constant relationship between the pressure-sensitive processing signal Sd and the reference value, and hence preventing abnormalities from occurring in the sensitivity increase of the pressure-sensitive means 10 and obtaining long-term reliability.
FUKUDA YU
FUJII YUKO
Hiroki Naito
Daisuke Nagano