According to one embodiment, a control device includes: a control circuitry configured to control an electric motor; and a failure sensing circuitry configured to sense a failure of the electric motor, wherein the failure sensing circuitry executes frequency analysis concerning an electric signal for driving the electric motor, calculates a phase of the electric signal, calculates a phase difference between a phase of a fundamental wave of a power supply frequency of the electric signal and the calculated phase of the electric signal, extracts a first signal indicating an outflow component from the electric motor based on a calculation result of the phase difference, extracts a second signal indicating an inflow component to the electric motor based on the calculation result of the phase difference, and senses the failure based on the first signal.

According to one embodiment, a control device includes: a control circuitry configured to control an electric motor; and a failure sensing circuitry configured to sense a failure of the electric motor, wherein the failure sensing circuitry executes frequency analysis concerning an electric signal for driving the electric motor, calculates a phase of the electric signal, calculates a phase difference between a phase of a fundamental wave of a power supply frequency of the electric signal and the calculated phase of the electric signal, extracts a first signal indicating an outflow component from the electric motor based on a calculation result of the phase difference, extracts a second signal indicating an inflow component to the electric motor based on the calculation result of the phase difference, and senses the failure based on the first signal.

A circuit for an inductive conductivity sensor comprises: a secondary coil having a first coil terminal and a second coil terminal, a switch having a first switch terminal, a second switch terminal, a third switch terminal, a first potential terminal, and a control unit having a first control terminal and a second control terminal, wherein the first coil terminal is connected to the first control terminal and the second coil terminal is connected to the first switch terminal, wherein the second switch terminal is connected to the first potential terminal and the third switch terminal is connected to the second control terminal.

A circuit for an inductive conductivity sensor comprises: a secondary coil having a first coil terminal and a second coil terminal, a switch having a first switch terminal, a second switch terminal, a third switch terminal, a first potential terminal, and a control unit having a first control terminal and a second control terminal, wherein the first coil terminal is connected to the first control terminal and the second coil terminal is connected to the first switch terminal, wherein the second switch terminal is connected to the first potential terminal and the third switch terminal is connected to the second control terminal.

Provided is a sample inspection apparatus capable of identifying a capacitive fault or a potential faulty point where an electrical tolerance is low. The sample inspection apparatus includes: a charged particle optical system configured to irradiate a sample 19 with a charged particle beam; a first probe 21a configured to come into contact with the sample; an amplifier 23 having an input terminal to which the first probe is connected; and a phase detection unit 40 to which an output signal of the amplifier is input, in which an AC voltage is applied to the first probe, and the phase detection unit detects the output signal of the amplifier using a reference signal synchronized with the AC voltage and having the same frequency as the AC voltage.

Provided is a sample inspection apparatus capable of identifying a capacitive fault or a potential faulty point where an electrical tolerance is low. The sample inspection apparatus includes: a charged particle optical system configured to irradiate a sample 19 with a charged particle beam; a first probe 21a configured to come into contact with the sample; an amplifier 23 having an input terminal to which the first probe is connected; and a phase detection unit 40 to which an output signal of the amplifier is input, in which an AC voltage is applied to the first probe, and the phase detection unit detects the output signal of the amplifier using a reference signal synchronized with the AC voltage and having the same frequency as the AC voltage.