Sensing Device

A sensing device which senses, using a piezoelectric vibrator in which an excitation electrode is respectively formed on one surface side and the other surface side of a crystal piece and an adsorbing layer for adsorbing a sensing target in a sample solution is provided on the excitation electrode of the one surface side, the sensing target being adsorbed by the variation of the natural frequency of the piezoelectric vibrator, said sensing device, comprising:

• (1) a main body having an oscillation circuit for oscillating the piezoelectric vibrator, a measuring section for measuring a concentration of the sending target based on an oscillation output from said oscillation circuit, a storage section for storing data in which a plurality of sensing targets and their standard concentrations are corresponded to each other, a data processing section for reading out the standard concentration corresponding to the sensing target from the storage section and comparing the standard concentration with a concentration detection value detected by the measuring section;
• and an output section for outputting a comparison result compared by said data processing section;
• (2) a piezoelectric sensor having a substrate on which wirings are formed, the piezoelectric vibrator provided on the substrate in parallel with the substrate and having the excitation electrode on the other surface side thereof provided to face a space divided from an accommodating region for the sample solution, a unit being provided to the substrate and holding an identification code corresponding to the sensing target sensed by the piezoelectric vibrator, terminal portions provided on the substrate and electrically connected to the excitation electrodes of the piezoelectric vibrator via the writings, and a case surrounding a space above the one surface side of the piezoelectric vibrator to form the accommodating region for the sample solution which is brought into contact with the absorbing layer, and having a fill port for the sample solution formed on an upper surface thereof, and is structured to enable the terminal portions to be connected to terminals on a side of said main body by inserting the substrate into an insertion port of said main body;
• and
• (3) a reading unit being provided to said main body and reading the identification code of said piezoelectric sensor attached to said main body to determine the sensing target.