GRAS 67HA User manual

Instruction Manual
www.gras.dk
LI0106 – 10 November 2017
G.R.A.S. 67HA 1 m Sound Power Hemisphere Kits

2LI0106 – 10 November 2017
Revision History
Any feedback or questions about this document are welcome at [email protected].
Revision Date Description
1 11 August 2014 First release
2 28 October 2015 Caution about the use of non-G.R.A.S. cables added to the
section “Mounting Microphone Sets and Cables”
3 10 December 2015 Number of cable clips included in the delivery corrected.
4 15 August 2016 Configuration naming on page 25 corrected (67HA-03 and
67HA-08)
5 4 July 2017 42AG substituted for the obsolete 42AB
6 10 November 2017 Color coding for 4 and 10 channel versions updated
Copyright Notice
© 2016-17 G.R.A.S. Sound & Vibration A/S
www.gras.dk
Any technical documentation that is made available by G.R.A.S. is the copyrighted work of
G.R.A.S. and is owned by G.R.A.S.
The content in this document is subject to change without notice. G.R.A.S. Sound & Vibration A/S
is not liable or responsible for any errors or inaccuracies that may appear in this document.
Trademarks
Any product names mentioned in this document may be trademarks or registered trademarks of
their respective companies and are hereby acknowledged.

3
LI0106 – 10 November 2017
Contents
Introduction.................................................................................. 5
Standards ................................................................................................ 5
Applications .............................................................................................. 5
Plug & Play .............................................................................................. 5
Holders and Cables ................................................................................... 5
Delivered Items for 1 m Hemisphere ................................................. 6
Hemisphere Structure................................................................................. 6
4-channel Configurations ............................................................................ 7
10-channel Configurations .......................................................................... 8
20-channel Configurations .......................................................................... 9
Assembling the Hemisphere – Overview........................................... 10
Assembling the Hemisphere Structure ............................................. 12
Introduction ............................................................................................. 12
Assembling the A-Layer (Bottom) ............................................................. 14
Assembling the B-Layer (Top) .................................................................... 15
Assembling the Circle ............................................................................... 16
Finishing the Assembly of the Structure ...................................................... 17
Mounting Microphone Sets and Cables ............................................ 18
Mounting the Microphone Holders ............................................................ 18
Mounting Microphone Sets and Cables ....................................................... 21
Technical Specifications................................................................ 22
Ordering Information.................................................................... 23
4-Channel Hemispheres .......................................................................... 23
10-Channel Hemispheres ......................................................................... 24
20-Channel Hemispheres ......................................................................... 25
Accessories ............................................................................................. 26
Calibration, Warranty and Service................................................... 27
Verification and Calibration ....................................................................... 27
Warranty................................................................................................. 27
Service and Repairs.................................................................................. 27

4LI0106 – 10 November 2017

5
LI0106 – 10 November 2017
Introduction
If you have ever tried to configure and use a sound power setup based on microphones mounted
on single tripods around your DUT, you will surely appreciate G.R.A.S.’ new sound power hemi-
sphere. The hemisphere will hold and position the measurement microphones according to the
standards and has been designed with focus on your workflow; it is very easy to assemble and
it is easy to position and access the DUT. Furthermore, in best G.R.A.S. tradition it is optimized
acoustically for correct and repeatable measurement data.
The structure is made portable to achieve a high degree of freedom of location. This, combined
with the easy, tool-less assembly in minutes, enables you to save expensive hemi-anechoic
chamber time and to offer on-site sound power diagnostics.
Standards
The G.R.A.S. 67HA 1 m Sound Power Hemisphere is compliant with the ISO 3744, 3745
and 3746 (ANSI S12.54, S12.55, S12.56) standards and accommodate for 4, 10 and 20
microphone positions. These are clearly marked to ease the mounting and maintain measurement
repeatability.
Applications
Depending on the size and the emitted acoustic level of the DUT, the hemisphere will allow
sound power measurements on everything from small sized personal electronics to office ma-
chines and IT products, household appliances, power tools and smaller engines. The only restric-
tion is that the characteristic dimension of the DUT may be no more than half the measurement
radius. See the aforementioned standards for further details.
Plug & Play
The microphone sets can be connected directly to all professional measurement systems and are
as indicated available for both CCP and 7-pin LEMO inputs. If your system platform supports
intelligent transducers according to IEEE 1451.4 (TEDS), the system can be set up to identify the
microphone properties and position in the array.
Holders and Cables
The pre-configured hemispheres are delivered with microphone set holders that will fit all 3
microphone types. Respective cables and cable clips are included.

6LI0106 – 10 November 2017
Delivered Items for 1 m Hemisphere
The G.R.A.S. 67HA 1 m Hemisphere is delivered in two cases, one containing the parts for the
structure, microphone holders, cables and cable clips, the other containing the parts for configur-
ing the hemisphere with microphone sets and cables.
It can be ordered for delivery in two flight cases, for further information, refer to “Accessories” on
page 26.
Hemisphere Structure
Delivered Items for 1 m Hemisphere Structure
6-pole Top
Connecting Piece
RA0254
4-pole
Connecting Piece
6 x RA0255
Vertical Pole
6 labeled A1 to A6
6 labeled B1 to B6
Horizontal Pole
6 x GR1560K
Foot
6 x RA0253
Bottom Strip
6 x RA0292
Finger Screws
(spare, 5 of each) for:
Microphone Holders and
Connecting Pieces
Strip Set for
Center Location
RA0293
GS0635
B ( 1 :2 )
C ( 1 : 1 )
B
GS0636_K05
A ( 1 : 1 )
B ( 1:1 )
A
B

7
LI0106 – 10 November 2017
4-channel Configurations
Delivered Microphones and Accessories for 4-Channel Configuration
ISO 3746:2010 / ANSI S12.56
G.R.A.S. 67HA-04 with CCP Microphone Sets
½" CCP
Microphone Set
4 x 46AE
10 m Cable,
BNC to BNC
4 x AA0037
Microphone Holder
incl. finger screw
3 x RA0259
Spacer for
Microphone Holder,
28 mm
4 x GR1572
Top Microphone
Holder
RA0261
Cable Clip
50 x KE0130
G.R.A.S. 67HA- 01 with LEMO Microphone Sets
½" LEMO
Microphone Set
4 x 46AF
10 m Cable
LEMO to LEMO
4 x AA0009
Microphone Holder
incl. finger screw
3 x RA0259
Spacer for
Microphone Holder,
18 mm
4 x GR1571
Top Microphone
Holder
RA0261
Cable Clip
50 x KE0130
G.R.A.S. 67HA-07 with Low Noise Microphone Sets
½" Low-noise
Microphone Set
4 x 40HL
10 m Cable,
LEMO to LEMO
4 x AA0009
Microphone Holder
incl. finger screw
3 x RA0259
Cable Clip
50 x KE0130
Top Microphone
Holder
RA0261
F-F ( 1 : 2 )
F
F
198
28
18 188
170
F-F ( 1 : 2 )
F
F
198
28
18 188
170
F-F ( 1 : 2 )
F
F
198
28
18 188
170
F-F ( 1 : 2 )
F
F
198
28
18 188
170
F-F ( 1 : 2 )
F
F
198
28
18 188
170

8LI0106 – 10 November 2017
10-channel Configurations
F-F ( 1 : 2 )
F
F
198
28
18 188
170
F-F ( 1 : 2 )
F
F
198
28
18 188
170
F-F ( 1 : 2 )
F
F
198
28
18 188
170
F-F ( 1 : 2 )
F
F
198
28
18 188
170
F-F ( 1 : 2 )
F
F
198
28
18 188
170
Delivered Microphones and Accessories for 10-Channel Configuration
ISO 3744:2010 / ANSI S12.54
G.R.A.S. 67HA-05 with CCP Microphone Sets
½" CCP
Microphone Set
10 x 46AE
10 m Cable,
BNC to BNC
10 x AA0037
Microphone Holder
incl. finger screw
9 x RA0259
Spacer for
Microphone Holder,
28 mm
10 x GR1572
Top Microphone
Holder
RA0261
Cable Clip
50 x KE0130
G.R.A.S. 67HA- 02 with LEMO Microphone Sets
½" LEMO
Microphone Set
10 x 46AF
10 m Cable
LEMO to LEMO
10 x AA0009
Microphone Holder
incl. finger screw
9 x RA0259
Spacer for
Microphone Holder,
18 mm
10 x GR1571
Top Microphone
Holder
RA0261
Cable Clip
50 x KE0130
G.R.A.S 67HA-08 with Low Noise Microphone Sets
½" Low-noise
Microphone Set
10 x 40HL
10 m Cable,
LEMO to LEMO
10 x AA0009
Microphone Holder
incl. finger screw
9 x RA0259
Cable Clip
50 x KE0130
Top Microphone
Holder
RA0261

9
LI0106 – 10 November 2017
20-channel Configurations
F-F ( 1 : 2 )
F
F
198
28
18 188
170
F-F ( 1 : 2 )
F
F
198
28
18 188
170
F-F ( 1 : 2 )
F
F
198
28
18 188
170
F-F ( 1 : 2 )
F
F
198
28
18 188
170
F-F ( 1 : 2 )
F
F
198
28
18 188
170
Delivered Microphones and Accessories for 20-Channel Configuration
ISO 3745:2010 / ANSI S12.55
G.R.A.S. 67HA-06 with CCP Microphone Sets
½" CCP
Microphone Set
20 x 46AE
10 m Cable,
BNC to BNC
20 x AA0037
Microphone Holder
incl. finger screw
20 x RA0259
Spacer for Micro-
phone Holder,
28 mm
20 x GR1572
Cable Clip
50 x KE0130
G.R.A.S. 67HA-03 with LEMO Microphone Sets
½" LEMO
Microphone Set
20 x 46AF
10 m Cable
LEMO to LEMO
20 x AA0009
Microphone Holder
incl. finger screw
20 x RA0259
Spacer for Micro-
phone Holder,
18 mm
4 x GR1571
Cable Clip
50 x KE0130
G.R.A.S 67HA-09 with Low Noise Microphone Sets
½" Low-noise
Microphone Set
20 x 40HL
10 m Cable,
LEMO to LEMO
20 x AA0009
Microphone Holder
incl. finger screw
20 x RA0259
Cable Clip
50 x KE0130

10 LI0106 – 10 November 2017
Assembling the Hemisphere – Overview
The G.R.A.S. 1 m Hemisphere for sound power measurements consists of a basic structure
common to all applications. This structure can be configured for 4-channel, 10-channel and
20-channel measurements. Below is shown a quick overview of the assembly of the hemisphere
and the mounting of microphones for a 10-channel configuration. A detailed description of the
assembly is given in the following sections.
Fig. 1. The basic hexagonal layer.
Fig. 2. The basic layer and four out of six legs of the vertical structures assembled.