| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pH meter which has a structure capable of exactly measuring a pH value of a sample liquid with high purity whose pH buffering capacity is low and conductivity is also low even when measurement of the pH value is repeated in a pH meter which has an ion-sensitive field effect transistor. <P>SOLUTION: Since the pH meter is formed so that an equivalent circle diameter on the cross section perpendicular to an axial direction of a tubular part 13 of a liquid junction 12 becomes 3 mm or more, the pH value of the sample liquid with high purity whose pH buffering capacity is low and conductivity is also low is exactly measured, namely, measurement of the pH value with successful reproducibility is easily attained with respect to rainwater, etc. in the pH meter which has the ion-sensitive field effect transistor (ISFET). <P>COPYRIGHT: (C)2012,JPO&INPIT |
