What is the measurement Spectrum?
From BS EN 60704-1:2010+A11:2012 Page 10, Section 4.1 Paragraph 3
The preferred noise emission quantity is the A-weighted sound power
level, LWA, in decibels
It is not correct to assume that a peak at 10kHz is outside the measurement range - you can reduce your 75dB measurement by -2.5dB according to the curve shown above.
What is the procedure?
Page 11 Paragraph 1
According to this standard, two principal methods exist, the direct
method and the comparison method, as described in 4.2 and 4.3 below.
These two methods can be used alternatively.
And then subsequently in Page 11 Section 4.2
The direct method can be used only for measurements in qualified test environments
according to ISO 3744 for free field conditions over reflecting plane(s), and according to ISO
3743-2 for special reverberation test rooms.
and Page 11 Section 4.3
The comparison method for measurement is explicitly described in ISO
3743-1 and in ISO 3743-2.