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Instruction Manual

 

Sound Intensity Probe Type 50AI

 

G.R.A.S.

Sound & Vibration

Skovlytoften 33, 2840 Holte, Denmark

 

www.gras.dk

Summary of Contents for 50AI

Page 1: ...Instruction Manual Sound Intensity Probe Type 50AI G R A S Sound Vibration Skovlytoften 33 2840 Holte Denmark www gras dk ...

Page 2: ...Revision 6 June 2014 Sound intensity Probe Type 50AI ...

Page 3: ...s A and B 9 2 2 Sound intensity Axis 9 3 Output Socket 11 3 1 Use with Power Module Type 12AB 11 4 Handling and Assembling the Probe 12 4 1 The Microphones 12 4 2 Probe Design 12 4 3 Physical Strength 12 4 4 Assembling the Probe 12 4 5 Using the Windscreen 14 5 Specifications 16 5 1 All versions 16 5 2 Version B 16 5 3 Version C 16 5 4 Version D 17 5 5 Version HP 17 5 6 Version LD 17 ...

Page 4: ...ones Type 40AI Fig 1 2 two G R A S microphone preamplifiers Type 26AA solid spacers remote control handle and connection cable The probe is adjustable durable and fully complies with the following requirements IEC 61043 Electroacoustics Instruments for the Measurement of Sound Intensity Meas urements with Pairs of Pressure Sensing Microphones 1993 for Class 1 Sound intensity probes Fig 1 1 The Sou...

Page 5: ... 8 The Type 50AI is delivered in a carrying case similar to the one shown in Fig 1 2 complete with microphones preamplifiers standard accessories and a remote control handle 1 1 1 Microphones The microphones Fig 1 3 are high sensitivity free field condenser microphones with a uniquely designed pressure equalization system that ensures extremely well defined phase characteristics The microphones an...

Page 6: ...s as described in the proposed standard ISO DIS 9614 2 for sound power measurements using sound intensity measurements Fig 1 3 Showing similar pairs of phase matched microphone cartridges Above Type 40AK which includes spacers and three adapters for preamplifiers as supplied with the Type 50AI Below Type 40AI which includes cartridges only Fig 1 4 Pair of Preamplifiers Type 26AA supplied with the ...

Page 7: ...of suppliers such as 01dB Müller BBM and Neutrix Cortex Can be used directly with the G R A S Intensity Module Type 12AB see also section 3 1 which provides all necessary voltages for the remote control functions and powering the pream plifiers The Intensity Module Type 12AB which is battery operated has two standard BNC output sockets for connecting to analysers that don t have special microphone...

Page 8: ...fier inputs Type 50AI version D Similar to version B but uses an internal 9 V battery already fitted on delivery for enabling its remote control functions Fig1 7 shows how to gain access to the battery Type 50AI version HP Has built in remote control functions for direct connection to and control of Hewlett Packard analysers such as the types HP 3569A and HP 35670A Opt UK4 Both of these analysers ...

Page 9: ... prior to assembly RA0263 100 mm spacer RA0264 50 mm spacer RA0265 25 mm spacer RA0266 12 mm spacer GR0040 Spacer cup RA0003 Straight adapter Pair of Type 26AA preamplifiers Type 40AI Pair of phase matched microphones Pair of RA0001 Right angled adapters Output socket Remote control buttons Telescopic arm Preamplifier inputs Swivel head ...

Page 10: ... by an acoustic wave front see Fig 2 2 When this happens this should be interpreted as a posi tive component of the sound intensity in the direction from microphone A to microphone B 2 2 Sound intensity Axis Fig 2 2 illustrates the origin and direction of positive sound intensity vectors This positive direction is always from microphones A to B The origin of the sound intensity axis lies on the ge...

Page 11: ...11 Fig 2 2 Showing the microphones A and B which correspond with channels A and B respectively A is the leading microphone and is struck first by a sound wave A B Direction of positive intensity Type 40AK pair Origin of intensity axis A leading mic B trailing mic ...

Page 12: ...ype 50AI When lit the red LED is signalling Request To Send the white LED is signalling Data Terminal Ready By suitably programming the analyser s computer s software measurements and data acquisi tion can be controlled interactively via the push buttons and LEDs Fig 3 1 12 pin LEMO female socket 1B external view The four inner pins are for connecting directly to an RS232 computer port Fig 3 2 9 p...

Page 13: ... Sound intensity Probe can be critically affected by even very small vibrations in the conductors carrying the raw signals from the microphones Therefore the preamplifiers are mounted in rigid contact with the microphones via short adapters right angled and or straight This also eliminates problems with non matching capacitances between microphones and preamplifiers which could give rise to phase ...

Page 14: ...Right angle adapter for a symmetrical probe or on the Straight adapter RA0003 for a straight probe configuration Remove the yellow protection caps from the two Preamplifiers Type 26AA and mount the microphone adapter assemblies on the preamplifiers Screw the Spacer cup GR0040 onto the protection grid of one of the microphones Select an appropriate spacer see Fig 5 1 for working frequency ranges fr...

Page 15: ... leading microphone should be connected to input channel A see section 2 1 4 Connect the probe to the analyser via the appropriate adapter cable depending on the specific type of analyser The functions of the operating buttons and indicating LEDs on the control handle are determined by the analyser in use and information about these should be found in the instruction manual of the given analyser s...

Page 16: ...he left straight setup On the right the branch for a symmetrical setup RA0003 Straight adapter RA0001 Right angled adapter GR0040 Spacer cup RA0266 Spacer Type 40AI Matched pair of microphones Type 26AA Preamplifier Type 26AA Preamplifier RA0001 Right angled adapter Type 26AA Preamplifier Straight Symmetrical ...

Page 17: ... Operating Temperature Range 5 C to 40 C Weight 0 4kg 0 9lbs Version B Accessories included Windscreen AI0001 5 2 Version B Remote control handle Built in remote control functions for 01dB analysers Two buttons for averaging control and two LEDs for status indication and overload indication Accessories included 5m cable AA0021 Adapter cable AC0002 12 pin LEMO to 2x7 pin LEMO plus remote control ma...

Page 18: ...uilt in remote control functions for Hewlett Pakard analysers One button for measurement control LEDs for status indication and overload indication Accessories included 3m cable AA0040 Adapter cable AC0006 12 pin LEMO to 2x7 pin LEMO plus remote control male 15 pin D sub plug 5 6 Version LD Remote control handle Built in remote control functions for Larson Davies analysers LD3000 or LD2900 One but...

Page 19: ...cer note the extend ed high frequency range WEEE directive 2002 96 EC CE marking directive 93 68 EEC Manufactured to conform with RoHS directive 2002 95 EC G R A S Sound Vibration continually strives to improve the quality of our products for our customers therefore the specifications and accessories are subject to change 100 1k 10k 10 100k 12 mm RA0266 25 mm RA0265 50 mm RA0264 100 mm RA0263 d Fr...

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