抄録
Pressure and temperature characteristics of in-situ sensors have a big influence on measurements. A pH sensor using ISFET (Ion Sensitive Field Effect Transistor) is regarded as a suitable sensor for measurement pH at deep sea, however, its pressure and temperature characteristics were seldom studied. So, in this paper, we study the pressure and temperature characteristics of ISFET-pH sensor by the structural analysis and by the laboratory experiments, and then consider a new structure which can decrease the pressure effects on ISFET-pH sensor, and investigate these effects on the actual measurement in deep sea. From experimental and actual measurement results, we estimate the applications and efficiency of ISFET-pH sensor. By the results of structural analysis, if the structure of the sensor has sufficient strength for practical use, pressure effects occur. The experimental results shows the pressure and temperature characteristics have large individual difference. But by the results of structural improvement analysis, the pressure effects can be reduced by the change in construction material of the sensor. The actual measurement in deep sea indicates that the temperature characteristics depends on pressure, and show a problem of the present way of calibration that is to calibrate the effects of pressure and temperature, respectively.At the same time, it is also shown that the sensor has high sensitivity, good responsibility, wide application and good efficiency.
