Model 90 Quantifier Sound Level Meter
Page 17
Using an external power supply
The MODEL 90 can be used with an
external power supply. When the
external supply is connected, the MODEL
90 switches automatically from the
internal battery power.
When the external power is either
removed or switched off, the instrument
will automatically switch back to the
internal battery supply.
When an external supply is connected, the display of the instrument will show a symbol
in the top right corner as shown below.
Windshield
The MODEL 90 Series can be used with a 90mm Foam Windshield which will reduce the
noise levels generated by air turbulence over the microphone capsule.
The windshield can also be used to protect the microphone capsule of the Sound Level
Meter from dust and fluids which may affect the performance of the instrument. To use
the Windshield, push the hole in the windshield over the microphone of the Sound Level
Meter. The Windshield must be removed before the Sound Level Meter can be
calibrated.
NK:70 Random Incidence Adaptor
The NK:70 Random Incidence Adaptor is designed to modify the
response of the microphone capsule from Free Field to Random
Incidence in order to comply with the requirements of ANSI
S1.4.
For instruments supplied for use outside of the USA, this
adaptor may not be supplied. For further details, please contact
your local representative.
To fit the NK:70 Random Incidence Adaptor, push the adaptor
over the microphone grill. Do not attempt to remove the
microphone grill as this may cause damage to the capsule.
To calibrate the instrument fitted with the microphone capsule,
remove the NK:70 Adaptor and follow the instructions supplied
with the instrument. Do Not attempt to calibrate the instrument
with the NK:70 fitted.
