MK:437 & MK:438 Outdoor Microphone
MK:437 & MK:438 Outdoor
Microphone User Manual
This manual, the software to which it relates, the
program code and drawings are all:
© Copyright Cirrus Research plc 1989-2001
MK:437 & MK:438 Outdoor Microphone
Page 2
The content of this manual, any illustrations, technical information and descriptions within this document
were correct at the time of going to print. Cirrus Research plc reserves the right to make any changes
necessary, without notice, in line with the policy of continuing product development and improvement.
No part of this publication may be duplicated, reprinted, stored in a data processing system or transmitted
by electronic, mechanical, photographic or other means, or recorded, translated, edited, abridged or
expanded without the prior written consent of Cirrus Research plc.
No liability is accepted for any inaccuracies or omissions in this manual, although due care has been taken
to ensure that is it complete and accurate as possible.
Accessories supplied by Cirrus Research plc have been designed for use with the instrumentation
manufactured by Cirrus Research plc. No responsibility is accepted for damage caused by the use of any
other parts or accessories.
In order to take account of a policy of continual development, Cirrus Research plc reserves the right to
change any of the information contained in this publication without prior notice.
Produced by Cirrus Research plc, Acoustic House, Bridlington Road, Hunmanby, North Yorkshire, YO14 0PH.
© Copyright Cirrus Research plc 2001
Reference Number 01/01/MK:437 & MK:438/01
Document Printing Date 5 December 2001
MK:437 & MK:438 Outdoor Microphone
Page 3
MK:437 & MK:438 Outdoor Microphone System Page 4
Overview Page 4
Messages & Symbols Page 4
MK:43x Variants Page 5
Outdoor Microphone Page 6
Preparing for use Page 7
Assembling the Instrument Page 7
Connecting Cables Page 8
MK:438 Outdoor Microphone System Connections Page 9
Connections Page 9
Power Supply Page 9
Output Voltage Page 10
Guarantee Page 11
Cirrus Research Offices Page 11
MK:437 & MK:438 Outdoor Microphone
Page 4
MK:437 & MK:438 Outdoor Microphone System
Overview
The MK:43x outdoor microphone system is designed to be used as part of a portable
semi-permanent acoustic measurement system. It is powered by the sound level meter
or data logger to which it is connected via the screened and waterproof cable.
The microphone system in its standard form is not equipped with a separate rainshield,
relying instead on a windshield to prevent rain reaching the microphone capsule
membrane.
Messages & Symbols
Messages are used in this manual to bring important information to your
attention. The different message types are indicated as shown below.
Pay attention! A caution informs you that improper use of the equipment or
failure to follow instructions may cause data loss or may damage the
equipment.
Please read.
A note is a hint or advice that helps you make best use of the
equipment and accessories.
Normally, the MK:43x is use in conjunction with one of the Cirrus Research plc outdoor
measurement kits which contain the required sound level meter and have a waterproof
gland on the side to connect to the microphone.
The capsule height can be set to be between 1,2 and 1,5 meters, the two
internationally agreed microphone heights for various outdoor measurements.
It should be noted that this will bring the birdspikes to a height at which they
could cause danger to the user. Care should be taken therefore when using
the birdspikes and persons should be protected from this danger.
MK:437 & MK:438 Outdoor Microphone
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MK:43x Variants
Two variants of the microphone system are available, with each meeting the type 1
requirements of IEC60651. The particular variant required is determined by the
instrument to which the microphone is to be connected. These options must be
specified when the microphone is ordered. The variants are designated by the
engraving of the preamplifier body, located at the top of the main body assembly.
Version For use with
MK:437 CR:703B Sound Level Meter
MK:438 CR:800A Sound Level Meter
The MK:43x Outdoor microphone system is usually supplied with an MK:224 ½” Type 1
pre-polarized electret capsule, or may be specified without a capsule, allowing the
microphone of an existing sound level meter to be used.
The MK:43x is supplied with a windshield to reduce wind noise and to protect the
capsule from adverse weather conditions. The top of the windshield carries the
bird-spikes which prevent birds from landing on top of the unit, thus causing extraneous
noise as well as soiling the windshield. The unit is also supplied with an integral tripod
allowing the unit to be used as supplied.
Be very careful when using the bird-spike as it is at eye height.
MK:437 & MK:438 Outdoor Microphone
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Outdoor Microphone
MK:437 & MK:438 Outdoor Microphone
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Preparing for use
Assembling the Instrument
Legs
1. Carefully remove the microphone unit from the transit case. The unit is secured
by two knurled bolts.
2. Remove the tripod leg carrier from the mast, and unscrew the legs from the
carrier.
3. Attach the tripod legs to the base unit. Ensure that the legs are inserted correctly
before tightening.
4. The legs of the tripod unit can be adjusted to accommodate uneven ground.
MK:437 & MK:438 Outdoor Microphone
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Microphone Capsule
The microphone capsule is usually attached to the system during transit. If this is not
the case, remove the outer windshield from the unit. Gently screw the capsule on to the
preamplifier and replace the windshield.
Connecting Cables
Ensure that all cables and connectors are secure before using the instrument.
This is particularly important when the instrument is to be used in an outdoor
environment. The connectors used on the MK:43x are weatherproof and
should be tight to ensure an effective seal.
The is supplied, as standard, with a 10m microphone cable which also carries the
electrostatic actuator signals where this option is fitted.
Connect the Microphone Cable to the main enclosure. Connect the other end to the
Microphone System.
JKG C
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MK:437 & MK:438 Outdoor Microphone
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MK:438 Outdoor Microphone System Connections
The MK:438 Outdoor Microphone system can be used to provide an electrical signal to
other noise measurement or recording equipment other than that supplied by Cirrus
Research plc.
The information below specifies the connections and power supply required by the
MK:438. Please note that the MK:438 is supplied
without
a microphone capsule unless
specified. The output voltage provided by the MK:438 will be determined by the
sensitivity of the microphone capsule used. The Class+ ½” Prepolarised Capsules from
Cirrus Research plc are suitable for use with the MK:438.
Connections
The output socket on the MK:438 is an Amphenol 10 Way Bayonet Connector Type
62-GB-12E12-10P
. Connection to this socket should be made using a Cable Socket
Type
62GB-56T-12-10S
with a Cable Clamp Type
62GB-585-12-10S.
A 10m ZL:410 Cable is supplied as standard with the MK:438. This cable may be
unterminated and uses the colours specified below.
Signal Pin Colour Connect to
+V A Red +15V
Signal Out B Blue Signal Out
Signal Ground C Braid/Screen 0V
Control Line D Black +15V
-V E Grey -15V
+VH F Brown +15V
not used G Turquoise
Signal Ground H Pink 0V
Signal Ground J Yellow 0V
Signal Ground K Orange 0V
not used Green
not used Cyan
Power Supply
The MK:438 Outdoor Microphone requires the following power supply:
A
+15v
A
-15v
A
0v (Ground)
MK:437 & MK:438 Outdoor Microphone
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Current consumption is less than 100mA. Connection of the power supply must be
made as specified in the connections above.
Output Voltage
The output voltage provided by the MK:438 is determined by the sensitivity of the
microphone capsule specified. The nominal output voltages for the Cirrus Research plc
Class+ capsules are specified below:
Capsule Nominal Output Voltage
MK:224 Class 1+ 50mV/Pa
MK:226 Class 1 37mV/Pa
MK:216 Class 2+ 37mV/Pa
MK:215 Class 2 37mV/Pa
For example, a 94dB Acoustic Calibrator will generate a Sound Pressure of 1Pa, giving
the nominal output levels specified above.
Please note that microphone capsules differ in sensitivity between units of the same
type. Care should be taken to ensure that noise measurement systems are calibrated
before use to ensure accurate measurement.
The output impedance of the system is less than 1Ù and the output is current limited to
30mA.
MK:437 & MK:438 Outdoor Microphone
Page 11
Guarantee
Cirrus Research plc offers a 12 month guarantee on all of their units. This covers
all parts and labour excepting only damage caused by the user. Because of the
unique fragility of microphones, only internal short or open circuits are accepted
as faults and not accident damage. The guarantee requires the user to return the
unit to their nearest authorised Cirrus Research plc Agent. This guarantee is in
addition to any statutory rights in your country.
Cirrus Research Offices
The addresses given below are the Cirrus Research plc offices. Cirrus Research
plc also have approved distributors and agents is many countries worldwide. For
details of your local representative, please contact Cirrus Research plc at the
address below. Contact details for Cirrus Research authorised distributors and
agents are also available from the Internet Web site at the address shown below.
Main Office
Cirrus Research plc
Acoustic House
Bridlington Road
Hunmanby
North Yorkshire
United Kingdom
YO14 0PH
Telephone: 01723 891655
Fax: 01723 891742
e-mail: [email protected]
Technical Support [email protected]
Web Site: www.cirrusresearch.co.uk
Germany
Cirrus Research Buro Dresden
Schlueterstrasse 29
01277 Dresden
Germany
Telephone: (+49) 351 316 0950
Fax: (+49) 351 316 0949
e-mail: [email protected]
Website www.cirrusresearch.de
USA
Cirrus Research
1307-A South Euclid Street
Anaheim
CA 92802
USA
Telephone 714 535 8647
Fax 714 535 8649
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