EXTECH 407764

User's Manual
Datalogging Sound Level Meter
Model 407764
•
Range: 30dB to 130dB
•
4-digit LCD Display with 0.1dB resolution
•
A and C Frequency Weighting
•
RS-232 PC Interface with
128,000 point datalogger and
Date / Time Stamp
•
Auto-Ranging
Introduction
Congratulations on your purchase of Extech’s Datalogging Sound Level Meter. The meter is
capable of performing all your noise measurements needs in addition to it’s capabilities for data
acquisition (direct data storage to a PC) or datalogging (data storage to internal memory for
later download). Data storage enables the user to save data, analyze data and generate
reports. This professional meter, with proper care, will provide years of safe reliable service.
Specifications
Applicable Standards
Accuracy
Frequency range
Measuring level
Frequency weighting
Microphone
Display
Bargraph
Sampling rate
Memory size
Datalogging sample rate
Time weighting
MAX
Level ranges
Auto range
Linearity range
Alarm function
AC output
DC output
Power supply
Battery life
AC adapter
Operating temperature
Operating humidity
Storage temperature
Storage humidity
Memory size
RS-232 Interface
Dimensions
Weight
Accessories
IEC651 Type 2, ANSI S1.4 Type 2
±1.5dB (under reference conditions)
31.5Hz - 8KHz
30 - 130dB
A and C
0.5” Electret condenser microphone
4-digit LCD
Resolution: 0.1dB
Display period: 0.5 sec.
50dB scale (1dB steps). Display period: 50mS; Auto-ranging:
100dB scale, 2dB steps
50mS
128,000 records / 255 sets (non-volatile memory)
1 to 86,400 seconds per record
FAST: 125mS, SLOW: 1 sec.
Maximum reading held
30-80dB, 40-90dB, 50-100dB, 60-110 dB, 70-120dB, 80-130dB
(Total of 6 ranges)
30 to 130dB
50dB
OVER indicator for readings higher than high limit.
UNDER indicator for readings lower than low limit.
0.707 Vrms at Full Scale
Output impedance approx. 600Ω
10mV / dB
Output impedance approx. 100Ω
Four 1.5V ‘AA’ batteries
Approx. 30 hrs continuous operation
Voltage: 6VDC
Voltage Ripple: < 100mVpp
Supply Current: > 100mADC
Socket: Pin Ground
Casing: Positive
External Diameter: 3.5mm
o
o
32 to 104 F (0 to 40 C)
10 to 80%RH
o
o
14 to 140 F (-10 to 60 C)
10 to 80%RH
128,000 data records with Date and Time Stamping
Baud rate: 9600bps
10.4 x 2.8 x 1.4” (265 × 72 × 35mm
Approx. 11.5 oz. (358g) including battery
Batteries, carrying case, screwdriver, windscreen, 3.5mm plug, RS-232
TM
cable , Windows compatible software.
Safety symbols
Meter is protected throughout by double insulation or reinforced
insulation.
CE
Complies with EMC
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Model 407764 Version 2.1 9/07
Meter Description
1. Microphone
2. Display
3. Power switch
4. Level range control switch
5. MAX hold switch
6. Frequency weighting switch
7. Response time select switch
8. AC output terminal
9. DC output terminal
10. CAL (calibration) pot.
11. External DC 6V power
12. RS-232 interface connector
13. Battery cover
14. Tripod mounting screw
15. Wind-screen
(Figure 1)
Display Description
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
Range selection
Date information
SPL: Instantaneous sound pressure level
Low-Battery
MAX: Maximum SPL value is held
Data recording
Measurement value
Memory full
Units
Frequency weighting (A/C)
TIME function
50dB level (Bargraph)
Over range
SLOW time response
FAST time response
Under range
(Figure 2)
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Model 407764 Version 2.1 9/07
Measurement Preparation
• Read the following safety information before attempting to operate the meter
• Use the meter only as specified or the meter's built-in protection may be impaired.
Maintenance & Cleaning
• Service not covered in this manual should be performed by qualified personnel
• Periodically wipe the case with a dry cloth. Do not use abrasives or solvents.
Battery Replacement
symbol appears on the LCD. Replace
When the battery voltage drops to a critical level, the
batteries as soon as possible after the battery symbol appears. The batteries (4 AA) are located
in the rear battery compartment. Remove the single Philips head screw (center rear) for access
to the batteries.
Measurements
Default Configuration
1. The meter's default configuration is as follows: 40 to 90dB, 'A' Frequency Weighting, and
'FAST' Response Time
2. The LCD will reflect the meter's configuration.
Measurement Considerations
1. Use a windscreen to cover the microphone in windy conditions.
2. Calibrate the meter often, especially if the meter has not been used for a long time.
3. Do not store/operate the meter in high temperature/humidity for long periods of time.
4. Keep the meter and the microphone dry.
5. Avoid severe vibration when using the meter.
6. Remove the battery when the meter will be stored for long periods of time.
Frequency Weighting
Change the Frequency Weighting by pressing the 'A/C' button. The 'A' or 'C' icon will display on
the right-hand area of the LCD.
Note: With ‘A’ weighting selected, the meter responds like the human ear (boosting and cutting
the noise amplitude over the frequency spectrum - see Appendix). ‘A’ weighting is used for
environmental measurements, OSHA regulatory testing, law enforcement, and workplace
design. Select ‘C’ weighting for flat response measurements (no boost or cut). ‘C’ weighting is
suitable for the sound level analysis of machines, engines, etc. Most OSHA related testing is
performed using 'A' Weighting and SLOW Response Time settings.
Response Time
Change the Response Time by pressing the 'FAST/SLOW' button. The 'FAST' or 'SLOW' icon
will display on the upper area of the LCD.
Note: Select FAST to capture noise peaks and noises that occur very quickly. In FAST mode,
the meter responds in 200ms. Select the SLOW Mode (meter responds in 500ms) to monitor a
sound source that has a reasonably consistent noise level or to average quickly changing
levels. Selection of Fast or Slow is determined by the application and any directives or
standards related to that application.
Auto/Manual Range
Press the LEVEL button up arrow to scroll through the following ranges: 30-80dB, 40-90,
50-100dB, 60-110, 70-120, 80-130 and 30-130dB (auto). The display will reflect the range for
each button press.
Notes: Use Auto Range when the noise source is relatively steady. Use one of the Manual
ranges may be required if the dB levels are changing over a wide range.
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Model 407764 Version 2.1 9/07
Operation
1.
2.
3.
4.
Power the meter and select the desired Response Time (Fast or Slow) and Frequency
Weighting (A or C).
Select the desired range.
Hold the instrument comfortably in hand or position on tripod. Point the microphone
toward the noise source, the sound pressure level will be displayed on the meter’s LCD
display.
When MAX (maximum hold) mode is selected by pressing the MAX key, the instrument
captures and holds the maximum noise level reading on the display. Press the MAX key
again to clear the MAX reading.
Calibration
Note that a Sound Level Calibrator is required. Set up the meter as listed in Step 1 below.
To calibrate the meter;
1.
2.
3.
4.
Display: SPL (dBA)
Response Time: FAST
Disable the MAX function
Range: 70 to 120dB.
Insert the microphone carefully into the sound
level calibrator.
Power the calibrator and adjust the Sound Level Meter’s
CAL potentiometer (as shown in figure at right) to match
the Calibrator’s output.
Typically, a Sound Level Calibrator will supply 94dB
or 114dB at 1KHz. Adjust the Sound Level Meter’s CAL
potentiometer for a 94dB or 114dB LCD display
(Figure-3)
Analog output
The 407764 has two analog output jacks located on its right side; one for AC and one for DC.
For DC, the meter transmits 10mv / dB. For AC the full scale value is 0.707V. The output
impedance is 600Ω for AC and 100Ω for DC.
The supplied 3.5mm stereo mini-plug can be used to assemble a cable to connect to either of
the meter’s analog output jacks. When using a stereo plug, like the one supplied, short the Tip
and the Ring (see diagram below). Ground (negative) connects to the Sleeve while the positive
signal is taken from the Tip/Ring. For mono plugs, ground connects to the Sleeve while the
positive signal is taken from the Tip. The meter output can then be transmitted to a chart
recorder, datalogger, or other data storage device.
(Figure 4)
Sleeve Tip
Sleeve Tip
Mono
Stereo
Ring
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Model 407764 Version 2.1 9/07
DataLogging
The internal memory of the meter can store up to 128,000 reading in up to 255 recording
sessions (called sets). Prior to beginning data storage, the meter’s real time clock and the
datalogger’s sample rate must be set using the supplied software. The clock is set in the
Control Panel window and the sample rate is set in the Logger window.
1.
Set the real time clock (if required).
2.
Set the sample rate (if required).
3.
To record data, press & hold the RECORD key for 3 seconds until the “RECORD” symbol
flashes once per second on the LCD. Press the Record key again to stop recording data.
4.
If the recording memory is full, the “FULL” symbol will appear on the LCD.
5.
To clear the recording memory press and hold the RESET key and power the meter. The
LCD will show the “dEL” icon letting the user know that the datalog memory has been
cleared.
6.
To Download or Record data via a PC refer to the PC Interface section below.
PC Interface
Connecting the Meter to a PC
Refer to Figure 5. Connect the 9-pin male connector to the Sound Level Meter, and connect the
9-pin female connector to the 9-pin COM1 PC port.
PC Requirements
(figure 5)
•
486 IBM compatible PC or better
•
One 3.5" high density disk drive
•
Available serial port.
•
4M Bytes H.D. storage space
•
EGA or VGA monitor
•
Windows 95, 98, 2000, NT, XP Operating System
•
3-button or 2-button Microsoft compatible
mouse. At least a 486 PC is recommended
for displaying all software windows with a
fast sampling rate (such as 1 second). If a 386/25 PC is used, you can only open one
window (LIST, GRAPH, ANALOG) at a time when using fast sampling rates.
Installing the Windows Application Program
Follow the instructions on the disk for installation. When installing the software, please use the
Visual Basic version (VB) on installation CD.
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Model 407764 Version 2.1 9/07
Software Control Panel Description
The Control Panel (Figure 6)
METER SIMULATION
The left side of the Control Panel window provides a replica of the meter’s front panel and
display.
MAX:
Hold and update maximum value
A/C
A/C weighting selection
RESET
Reboot and clear the data memory
F/S
Fast/Slow selection
REC
Enable datalogging
LEVEL
Set range
DATA ACQUISITION CONTROLS and DISPLAYS
MIN:
MAX:
TIME:
SAMPLING TIME
PC SAMPLING:
<--RESET-->:
SYSTEM TIME SET:
SAVE AS:
OPEN FILE:
FILE NAME:
START RECORDING:
STOP RECORDING:
EXIT
Displays the minimum value recorded
Displays the maximum value recorded
Displays the Real Time Clock Setting
Display of data acquisition sampling rate (Fig 7)
Opens data acquisition sampling rate selection box. (Datalogging
sample rate is set in the MEMORY “Logger” window)
Resets the MIN and MAX stored readings
Sets the meter’s clock to the value of the pc clock
Opens the data file storage window (*.dat)
Opens the data file retrieve window (*.dat) (Fig.8)
Displays name and location of data acquisition file
After opening a file, click to start recording.
Stop recording and close the file
Close program
(Figure-7)
Selecting the datalog sample rate
(Figure-8)
Opening a datalog file (*.dat)
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Model 407764 Version 2.1 9/07
DISPLAY SELECTIONS
(Figure-9)
GRAPH
(Figure-10)
LIST
(Figure 11)
ANALOG
Logger Window (memory setup/ data download)
The Logger window sets the sample rate of the meter’s internal memory and provides the
controls to download display and save stored data.
MEMORY
Displays memory size
REMAINING
Displays amount of
unused memory
TIME OF METER
When clicked,
downloads and
displays the meter’s
date and time
ID CODE
Numeric Identification
code. Enter the code
in the box and click on
the bar to store the
code.
SAMPLING
Datalogger sample
rate. Enter the sample
rate in the box (in
seconds) and click on
the SAMPLING bar to store the value.
NUMBER OF SETS
Click on the bar to download the stored data
TIME OF RECORDING Click on the bar to display sets downloaded. Click on a set to select
data for display
NUMBERS OF REC
Displays the number of records (data points) in the selected set.
SHOW DATA
Display, Save or Graph data from selected set
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Model 407764 Version 2.1 9/07
DATA DOWNLOAD PROCEDURE
1.
Click the MEMORY icon in the Control Panel screen.
2.
Click the NUMBERS OF SETS button, the number of sets will appear.
3.
Click on the TIME OF RECORDING button to view each recorded set.
4.
Click on a SET in the TIME OF RECORDING box. The number of records in the set will
appear and the data will be downloaded from meter to PC. Save to disk if desired.
5.
Click the SHOW DATA button for details on each record. Figure 13 shows the data list.
Select SAVE, PRINT, GRAPH, or EXIT from the menu choices.
Note: In the example for Figure 12, there are 3 sets of recorded data in memory. Set No. 3 has
15 records. Note: If you need to change the ID CODE or the SAMPLING time, click on the
desired parameter, type the changes and click on the bar.
(Figure-13) – List of datalogged set
(Figure-14) – Graph of datalogged set
(Figure-15) – Selecting a range of datalogged records
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Model 407764 Version 2.1 9/07
Calibration / Repair Services
Extech offers complete repair and calibration services for all of the products we sell. For
periodic calibration, NIST certification or repair of any Extech product, call customer service for
details on services available. Extech recommends that calibration be performed on an annual
basis to insure calibration integrity.
Warranty
EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects in parts
and workmanship for one year from date of shipment (a six month limited warranty applies on
sensors and cables). If it should become necessary to return the instrument for service during or
beyond the warranty period, contact the Customer Service Department at (781) 890-7440 ext. 210
for authorization or visit our website at www.extech.com (click on Contact Extech and go to Service
Department to request an RA number). A Return Authorization (RA) number must be issued before
any product is returned to Extech. The sender is responsible for shipping charges, freight, insurance
and proper packaging to prevent damage in transit. This warranty does not apply to defects resulting
from action of the user such as misuse, improper wiring, operation outside of specification, improper
maintenance or repair, or unauthorized modification. Extech specifically disclaims any implied
warranties or merchantability or fitness for a specific purpose and will not be liable for any direct,
indirect, incidental or consequential damages. Extech's total liability is limited to repair or
replacement of the product. The warranty set forth above is inclusive and no other warranty, whether
written or oral, is expressed or implied.
Support line (781) 890-7440
Technical support: Extension 200; E-mail: [email protected]
Repair & Returns: Extension 210; E-mail: [email protected]
Product specifications subject to change without notice
For the latest version of this User’s Guide, Software updates, and other
up-to-the-minute product information, visit our website:
www.extech.com
Extech Instruments Corporation, 285 Bear Hill Rd., Waltham, MA 02451
Copyright © 2005 Extech Instruments Corporation. All rights reserved
including the right of reproduction in whole or in part in any form.
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Model 407764 Version 2.1 9/07
Appendix - Typical ‘A’ Weighted Sound Levels
140
50 HP Siren (100')
130
120
Jet take-off (200')
Riveting machine
110
100
90
Subway (20')
Chain saw
Boiler room
80
Freight train (100')
Pneumatic drill (50')
70
Speech (1')
Vacuum cleaner (10')
60
Large Office
Large store
50
Residence
Small office
40
Residential area (night)
30
20
Sound studio
Whisper (5')
10
Threshold of hearing
0
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Model 407764 Version 2.1 9/07
Software Protocol
Data Protocol
Baud rate: 9600bps
Byte1
Byte2
Byte3
Byte4
Byte5
02
Status
Function
03
Leading byte
Ending byte
Status Byte2
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
0
Fast
C
Normal
Normal Normal
0
0
0
30-80
1
Slow
A
Max
Full
Rec
0
0
1
40-90
0
1
0
50-100
0
1
1
60-110
1
0
0
70-120
1
0
1
80-130
1
1
0
30-130
1
1
1
Function Byte3
2
Bit7
Bit6
Bit5
Bit4 (x10 )
Bit3-0 (x10)
0
Normal
Normal
Normal
00-19
1
OVER
UNDER
BT
Function Byte4
0
-1
Bit7-4 (x 10 )
Bit3-0 (x10 )
0
00-99
1
Command Protocol
Set time and date - Send 7 bytes
D
YY
MM
dd
hh
mm
ss
leading byte
year
month
date
hour
min
sec
Set sampling rate – Send 3 bytes
W
high byte
low byte
leading byte
1 – 65535 sec
Set ID code – Send 3 bytes
X
high byte
low byte
leading byte
1 – 65535
Get software version – Output “V” - Receive 1 byte (0 – 255)
Get system argument – Output “Y” – Receive 10 bytes
ID Code
Version
ID code
Data sets
Last address
Sample rate
2bytes
1 byte
1 byte
1 byte
3 bytes
2 bytes
Get time and date – Output “C” - Receive 6 bytes (YY+MM+dd+hh+mm+ss)
Receive 6 bytes (Sets+YY+MM+dd+hh+mm+ss+Status+Sample rate+Records)
Get Record – Output “K”+N records”
st
nd
Receive (YY+MM+dd+hh+mm+ss+Status+Sampling rate+Records+1 record+2
record+…+nth record)
Erase Command: “EEE” (3 bytes)
Switch Fast/Slow: “F” (1 byte)
Switch A/C: “A” (1 byte)
Switch range: “U” (up), “P” (down) (1 byte)
12
Set MAX spl; “M” (1 byte)
Stop Recording: “T” (1 byte)
Start Recording: “S” (1 byte)
Model 407764 Version 2.1 9/07