Recording apparatus, detection method, and storage medium

A recording apparatus comprising:

• a sensor including a light emitting element for emitting light to a recording medium, and a light receiving element for receiving the light emitted from the light emitting element and reflected by the recording medium, configured to, via the light emitting element and the light receiving element, measure a patch recorded on the recording medium by a recording head for performing recording on the recording medium based on image data;
• a calibration member configured to reflect light emitted from the light emitting element, and to be used to calibrate the sensor based on a result of optical measurement of the calibration member performed by receiving, via the light receiving element, reflected light reflected by the calibration member;
• and
• a detection unit configured to detect dirtiness of the calibration member based on the result of the optical measurement of the calibration member by using the sensor and a result of optical measurement of the calibration member performed before the measurement.