Tyco Electronics Japan G.k.

Heewon Jeong

Tsuyoshi Tanaka

Kenta Sato

Kazuo Hasegawa

A concentration measuring instrument includes a piezoelectric vibrator transmitting an ultrasonic wave into a solution contained in a cavity and detecting the ultrasonic wave reflected, a temperature sensor measuring a temperature of the solution, a drive circuit generating a drive signal driving the piezoelectric vibrator, a phase comparator performing a phase comparison between the drive signal and a detection signal, a frequency setting circuit making the drive circuit generate drive signals having sequentially different frequencies and monitoring a phase comparison result to detect a resonant frequency, and a Phase Locked Loop (PLL) circuit making a frequency of the drive signal follow the detected resonant frequency. A microcomputer determines a concentration of a solute in the solution on a basis of the frequency of the drive signal while the PLL circuit is being operated and a result of a temperature measurement by the temperature sensor.

Concentration measuring instrument

A printed circuit board comprises a board main body, a sensor, an external connection pad, and a hollow-structured electrical conductor. The board main body has a top face and a bottom face opposite the top face. The sensor is mounted on one of the top face and the bottom face of the board main body. The external connection pad is provided on the top face or the bottom face of the board main body opposite the sensor. The hollow-structured electrical conductor extends through the board main body and electrically connects the sensor to the external connection pad.

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Kanagawa, Japan

Heewon Jeong