PURPOSE: To continuously detect and record the change with time of electrostatic capacity or dielectric constant of each of a plurality of specimens with a minimized number of fittings or devices, by successively and automatically connecting an electrostatic capacity or dielectric constant detector to a plurality of specimens through a changeover operation effected by a dot determination signal generated in synchronism with a dot printing operation of a multipoint recorder.

CONSTITUTION: Simultaneously with the completion of locking of the BM of a recorder 5 for a dot 1, a signal synchronized therewtih is generated to close a relay 2R2 which connects an electrostatic capacity 1S2 of a specimen and an LCR meter 3. Under this state, the value of 1S2 is detected by the LCR meter 3 and is fed to the recorder 5 through an electrostatic capacity converter 4. When the LCR meter 3 and the converter 4 have been sufficiently stabilized, the BM of the recorder 5 is locked, and the value of 1S1 is recorded at a dot 2. Thereafter, the operation is successively shifted to 1S2, 1S3...1Sn, 1Sk. This operation is cyclically repeated, thereby allowing the electrostatic capacities (1S1W1Sn) and temperatues of n specimens to be automatically drawn on the recorder with a minimized number of fittings or devices and substantially continuously by selecting a proper recording paper feed speed.