Dell PowerEdge T110 II Technical Manual page 22

LpA-Op: A-Weighted sound pressure level. The system is placed in center of ISO7779 table, while the
acoustic transducer is located 150 cm above the floor and 50 cm in front of the equipment.
Prominent tones: Criteria of D.6 and D.11 of ECMA-74 11th ed. (2010) are followed to determine if
discrete tones are prominent. The system is placed in a rack with its bottom at 75-cm from the floor.
The acoustic transducer is at front bystander position, ref ISO7779 3rd (2010), Section 8.6.2.
PowerEdge T110 II Technical Guide 22