Head transducer with multiple resistance temperature sensors for head-medium spacing and contact detection

An apparatus, comprising:

• a head transducer configured to interact with a magnetic recording medium, a low-modulation or a non-modulation head-to-medium interface defined between the head transducer and the medium;
• a heater configured to actuate the head transducer;
• a modulator coupled to the heater and configured to modulate power supplied to the heater at a modulation frequency;
• a sensor situated at the head transducer and having a temperature coefficient of resistance, the sensor configured to sense for contact between the head transducer and the medium;
• and
• a detector coupled to the sensor, the detector configured to measure a response of the sensor and detect head-medium contact using a detection metric based on a change in resistance of the sensor and a change in heater power.

A method, comprising:

• modulating power supplied to a heater of a head transducer configured to interact with a magnetic recording medium, a low-modulation or a non-modulation head-to-medium interface defined between the head transducer and the medium;
• sensing for contact between the head transducer and the medium using a sensor having a temperature coefficient of resistance;
• measuring a response of the sensor;
• and
• detecting head-medium contact using a detection metric based on a change in resistance of the sensor and a change in heater power.