Acoustic Emission Sensor and Method For Checking Operating State of Acoustic Emission Sensor

A method for checking the operating state of an AE sensor, the method comprising:

• applying a pulse signal to an AE conversion element in the reference state through the output passage of an AE signal from the AE conversion element;
• calculating and storing the frequency characteristics of the AE signal output from the conversion element in accordance with the application of the pulse signal as reference frequency characteristics;
• applying a pulse signal to the AE conversion element in response to an operation check request signal;
• calculating the frequency characteristics of the AE signal output from the AE conversion element in accordance with the application of the pulse signal as operation check frequency characteristics;
• and
• comparing the operation check frequency characteristics with the reference frequency characteristics and judging that the sensor is normal when the difference is smaller than a predetermined amount or that the sensor is abnormal when the difference is greater than the predetermined amount, and outputting judgment results.