Contents
CHAPTER 1 .......................................................................................... 1
Introduction ........................................................................................................................................ 1
Sonus Variations ........................................................................................................................ 2
Sonus L...................................................................................................................................... 2
Sonus E ..................................................................................................................................... 3
Sonus I ....................................................................................................................................... 3
Sonus B ..................................................................................................................................... 3
CHAPTER 2 .......................................................................................... 4
Microphone ........................................................................................................................................ 4
Microphone Types ..................................................................................................................... 4
Free Field .................................................................................................................................. 4
Pressure ................................................................................................................................... 4
Random Incidence ............................................................................................................... 4
Microphone Polarisation ........................................................................................................ 4
Externally Polarised ............................................................................................................. 4
Pre-Polarised .......................................................................................................................... 4
Microphone Sensitivity ............................................................................................................ 5
Certifiable Calibration .............................................................................................................. 5
Removal of Microphone .......................................................................................................... 5
Pre-Amplifier Removal and Fitting ........................................................................................... 6
Models GA116L, GA116E, GA116I & GA216L-P .................................................... 6
Microphone Extension Cable (Models GA116L, GA116E & GA216L) ..... 6
CHAPTER 3 .......................................................................................... 7
Measuring Sound ............................................................................................................................ 7
Sound Level – General Advice ............................................................................................. 7
Reflections ..................................................................................................................................... 8
Time Weighting ........................................................................................................................... 8
Slow Weighting ..................................................................................................................... 8
Fast Weighting ...................................................................................................................... 8
Impulse Weighting – (Models GA116E, GA116L & GA216L Only) ........... 8
Frequency Weighting Filters ................................................................................................ 9
‘A’ Weighting .......................................................................................................................... 9
‘C’ Weighting .......................................................................................................................... 9
‘Z’ Weighting (Zero) – (Models ‘E’ & ‘L’ Only) ......................................................... 9
Overload and Under Range Conditions ........................................................................ 10
Overload Condition ............................................................................................................ 10
Under Range Condition .................................................................................................. 11
Measuring Ranges ................................................................................................................. 12
Changing Range – All models except GA257B and GA257L .................... 12
Lock Keypad – GA257B and GA257L ................................................................... 13
CHAPTER 4 ....................................................................................... 14
Getting Started .............................................................................................................................. 14
Models I and B .......................................................................................................................... 14
Models L and E ......................................................................................................................... 14
All Models ................................................................................................................................... 15
Keypad Layout – GA116, GA216 All Models ........................................................... 16
