Method of testing a head for contamination

1. A method of testing a head for contamination, the method comprising:

detecting a first touchdown power of the head, the head having a flying height actuator;

calculating a back-off power for the head using an estimated relationship between back-off power and touchdown power;

determining an operating power that is equal to the detected first touchdown power minus the calculated back-off power;

passing the head over a magnetic media one or more times while applying the determined operating power to the flying height actuator;

detecting a second touchdown power after passing the head over the magnetic media; and

determining whether contamination on the head exceeds a threshold amount based on the detected second touchdown power.

2. The method of claim 1 , further comprising calculating a difference between the first detected touchdown power and the second detected touchdown power, wherein the determining of whether contamination on the head exceeds a threshold amount is based on the calculated difference.

3. The method of claim 2 , wherein the determining of whether contamination on the head exceeds a threshold amount comprises comparing the calculated difference to a threshold touchdown power.

4. The method of claim 3 , wherein the comparing of the calculated difference with the threshold touchdown power further comprises determining whether the calculated difference is greater than the threshold touchdown power.

5. The method of claim 4 , wherein the threshold touchdown power is about 10 mW or greater.

6. The method of claim 1 , wherein passing of the head over the magnetic media comprises moving the head from the inner diameter to the outer diameter and back to the inner diameter.

7. A method of testing a head for contamination, the method comprising:

detecting an initial touchdown power of the head, the head having a flying height actuator;

calculating a back-off power for the head using an estimated relationship between back-off power and touchdown power;

applying an operating power to the flying height actuator that is equal to the detected initial touchdown power minus the calculated back-off power;

passing the head over a magnetic media a plurality of times while applying the operating power to the head;

detecting a subsequent touchdown power after each passing of the head over the magnetic media, thereby obtaining a plurality of subsequent touchdown powers; and

determining whether contamination on the head exceeds a threshold amount based on at least one of the subsequent touchdown powers.

8. The method of claim 7 , wherein the plurality of times comprises 10 to 12 times.

9. The method of claim 7 , wherein the plurality of times comprises 2 to 4 times.

10. The method of claim 7 , wherein each passing of the head over the magnetic media comprises moving the head from the inner diameter to the outer diameter and back to the inner diameter.

11. The method of claim 7 , further comprising calculating a difference between the initial detected touchdown power and each of the subsequent detected touchdown power, wherein the determining of whether contamination on the head exceeds a threshold amount is based on at least one of the calculated differences.

12. The method of claim 11 , wherein the determining of whether contamination on the head exceeds a threshold amount is based on the calculated difference having the highest value of the calculated differences.

13. The method of claim 11 , wherein the determining of whether contamination on the head exceeds a threshold amount comprises comparing the at least one of the calculated differences to a threshold touchdown power.

14. The method of claim 13 , wherein the comparing of the at least one of the calculated differences with the threshold touchdown power further comprises determining whether the at least one of the calculated differences is greater than the threshold touchdown power.

15. The method of claim 13 , wherein the threshold touchdown power is about 10 mW or greater.

16. A method of testing a head for contamination, the method comprising:

detecting a first touchdown power of the head at a plurality of discrete points along a radius of the magnetic media, the head having a flying height actuator;

calculating a back-off power for the head for each of the plurality of discrete points using an estimated relationship between back-off power and touchdown power;

determining an operating power for each of the plurality of discrete points, wherein the operating power for each of the plurality of discrete points is equal to the detected first touchdown power of a particular point minus a corresponding calculated back-off power for the particular point;

passing the head over a magnetic media one or more times while applying the determined operating power to the flying height actuator for each of the plurality of discrete points;

detecting a second touchdown power for each of the plurality of discrete points after passing the head over the magnetic media; and

determining whether contamination on the head exceeds a threshold amount based on the detected second touchdown power for at least one of the discrete points.

17. The method of claim 16 , further comprising calculating a difference between the first touchdown power and a corresponding second detected touchdown power for each of the plurality of discrete points, wherein the determining of whether contamination on the head exceeds a threshold amount is based on the calculated difference for at least one of the plurality of discrete points.

18. The method of claim 17 , wherein the determining of whether contamination on the head exceeds a threshold amount comprises comparing the calculated difference for the at least one of the plurality of discrete points to a threshold touchdown power.

19. The method of claim 18 , wherein the comparing of the calculated difference for the at least one of the plurality of discrete points with the threshold touchdown power further comprises determining whether the calculated difference for the at least one of the plurality of discrete points is greater than the threshold touchdown power.

20. The method of claim 19 , wherein the threshold touchdown power is about 10 mW or greater.

21. The method of claim 16 , wherein passing of the head over the magnetic media comprises moving the head from the inner diameter to the outer diameter and back to the inner diameter.