Patent ID: 8717045

Claim:
A microorganism number-measuring apparatus, comprising: a measurement container including a measurement liquid and an measurement electrode disposed in the liquid in an immersed state; a rotary driver for rotationally driving the measurement liquid in the measurement container; a bacteria-collection signal generator for feeding a bacteria-collection signal to the measurement electrode; a measurement signal generator for feeding a measurement signal to the measurement electrode; an output amplifier for amplifying an output of the measurement signal generator and an output of bacteria-collection signal generator; an I/V amplifier coupled with an output of the output amplifier via the measurement electrode; an impedance measuring unit coupled with the I/V amplifier, the measuring unit measuring impedance of the measurement liquid; a microorganism number-computing unit coupled with the impedance measuring unit, the number-computing unit computing a number of microorganisms present in the measurement liquid; a solution conductivity-computing unit coupled with the impedance measuring unit, the conductivity-computing unit computing an electric conductivity of the measurement liquid; and a warm-up section for performing warm-up of at least one of the I/V amplifier and the output amplifier, the solution conductivity-computing unit being coupled with the warm-up section, an output of the warm-up section being coupled with at least one of the I/V amplifier and the output amplifier via a warm-up switch, wherein, in a measurement setup mode, the solution conductivity-computing unit measures a solution electric conductivity of the measurement liquid, the warm-up section computes a warm-up signal by using the measured solution electric conductivity, the warm-up signal having a current identical in magnitude to a current flowing through the measurement electrode, and the warm-up section performs the warm-up by applying the warm-up signal to at least one of the I/V amplifier and the output amplifier.