BRUEL & KJAER HATS 4606, User Manual

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High-frequency Head and Torso Simulator (HF HATS) Type 5128 – User Manual 12
2.5.2 Positioning Aids on HF HATS – Types 5128-C/D Only
Fig.2.8 shows the positions of threaded fixing holes (all M3-threaded) which are provided at
various locations on HF HATS. These allow attachment of user-designed support structures for the
devices under test, if required. To help position devices under test, HF HATS has grids marked in
centimetres both horizontally and vertically around both ears.
Fig.2.8
The positions of the
fixing holes on HF
HATS. All dimensions
shown in mm
2.5.3 Data Disk Supplied with HATS
Each Type 5128 comes with a data disk containing calibration data as well as other relevant data
in ASCII format. The data disk contains calibration measurements for the mouth simulator, the
right ear simulator (Type 4620-R), and the left ear simulator (Type 4620-L). The calibration data
supplied is listed in Table 2.2. Only the listener free-field frequency response and the talker
frequency response (TFR) are measured individually for each HATS. The other measurements are
typical, and are stored in the ‘Typical Data’ directory. The variation between different HATS is
small and is mainly due to sensitivity variations between the ear simulators. Because of this, the
individual measurements can be used to ‘correct’ the typical measurements for a particular HATS.
Dividing the individual data in the file ‘LFR R-5128-C-111- xxxxxxx.csv’ by the 0 degrees typical
data in the file ‘LFR R, EL+0, AZ 0-360.txt’ will reveal the variation from the typical right ear
simulator sensitivity. This correction curve can be multiplied by any other ear measurements to
‘correct’ the typical curve. The same procedure can be applied for the left ear simulator.
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