Noise determination device

A noise determination device that determines, in an environment where periodic noise is generated, presence of noise on an input signal with a constant value that is output from an external device, the noise determination device comprising:

• a sampling unit that performs three samplings on the input signal;
• a sampling-interval setting unit that sets an interval between a first one and a second one of the samplings have a first value that is different from an integral multiple of a period of the periodic noise, and sets an interval between the first one and a third one of the samplings to have a second value that is different from an integral multiple of the period and is larger than the first value, the second value being equal to or larger than an interval that is large enough to fully attenuate the periodic noise;
• and
• a noise determination unit that determines that the noise is not superimposed on the input signal only when all values acquired by the first, second, and third samplings match one another.