MRC SL-4035SD, SL-4023SD Operation Manual

Sound Level Meter

SL-4035SD

Operation Manual

PLEASE READ THIS MANUAL CAREFULLY BEFORE OPERATION

Hagavish st. Israel 58817 Tel: [phone], Fax: [phone] [e-mail]

MRC.8.16

TABLE OF CONTENTS

1. FEATURES................................................................................ 1

2. SPECIFICATIONS..................................................................... 2

3. FRONT PANEL DESCRIPTION................................................

.

6

4. MEASURING PROCEDURE.....................................................

.

7

4-1 Sound Pressure Measurements (SPL)....................................... 7

4-2 Integrating Sound Level Meter Measurements (Leq).................

.

8

4-3 Data Hold.................................................................................... 10

4-4 Data Record ( Max., Min. reading )............................................. 11

5. DATALOGGER.......................................................................... 12

5-1 Preparation before execute datalogger function......................... 12

5-2 Auto Datalogger ( Set sampling time ≧ 1 second )..................

.

12

5-3 Manual Datalogger ( Set sampling time = 0 second )................ 14

5-4 Check time and sampleing time information............................... 14

5-5 SD Card Data structure..............................................................

.

15

6. Saving data from the SD card to the computer.......................... 16

7. ADVANCED SETTING..............................................................

.

18

7-1 Set clock time ( Year/Month/Date, Hour/Minute/ Second )......... 18

7-2 Set sampling time ......................................................................

.

19

7-3 Auto power OFF management ..................................................

.

19

7-4 Set beeper Sound ON/OFF........................................................

.

20

7-5 Decimal point of SD card setting................................................

.

20

7-6 SD memory card format.............................................................. 21

7-7 Frequency weighting to A or C setting..................................... 21

8. POWER SUPPLY from DC ADAPTER...................................... 22

9. BATTERY REPLACEMENT......................................................

.

23

10. RS232 PC serial interface........................................................ 23

11 CALIBRATION .........................................................................

.

25

12. FREQUENCY WEIGHTING CHARACTERISTICS

OF A & C NETWORKS............................................................

25

13. TIME WEIGHTING (FAST & SLOW)

CHARACTERISTICS...............................................................

26

14. PATENT................................................................................... 26

1. FEATURES

* Frequency and Time weighting are designed to meet IEC 61672 class 2.
* The meter with programmable integrating time provides precise linearity

over a wide range (100dB) and displays Leq and SPL measurements.

* A & C weighting networks comply with standards.
* 0.5" standard microphone head.
* Time weighting (Fast & Slow) dynamic characteristic modes.
* Build External calibration VR.
* Auto range & Manual range selection.
* Condenser microphone for high accuracy & long-term stability.
* Memory function to store the Max. & Min. value.
* Hold and Peak Hold functions.
*

Real time SD memory card Datalogger, it Built-in Clock
and Calendar, real time data recorder, sampling time set
from 1 second to 3600 seconds.

* Manual datalogger is available ( set the sampling

time to 0 second ), during execute the manual datalogger
function, it can set the different position ( location ) No.
( position 1 to position 99 ).

* Innovation and easy operation, computer is not need to

setup extra software, after execute datalogger, just take
away the SD card from the meter and plug in the SD card
into the computer, it can download the all the measured
value with the time information ( year/month/date/
hour/minute/second ) to the Excel directly, then user can
make the further data or graphic analysis by themselves.

* SD card capacity : 1 GB to 16 GB.
* LCD with green light backlight, easy reading.
* Can default auto power off or manual power off.
* Data hold, record max. and min. reading.
* Microcomputer circuit, high accuracy.
* Power by UM3/AA ( 1.5 V ) x 6 batteries or DC 9V adapter.
* RS232/USB PC COMPUTER interface.
* Heavy duty & compact housing case.

Leq, SEL, SPL, MAX-L, and MIN-L measurements.

1

2. SPECIFICATIONS

Circuit Custom one-chip of microprocessor LSI

circuit.

Display LCD size : 52 mm x 32 mm

LCD with green backlight ( ON/OFF ).

Measurement

SPL : Sound pressure level

Type

Leq : Equivalent Continuous Noise Level

Measurement 30 - 130 dB.
Range
Resolution 0.1 dB.
Function dB ( A & C frequency weighting ),

Time weighting ( Fast, Slow ),
Peak hold, Data hold
Record ( Max., Min. ).

Accuracy Characteristics of " A " frequency
(23 ±5 ℃)

weighting network meet IEC 61672
class 2

Under 94 dB input signal, the accuracy
are :

31.5 Hz ±3.5 dB
63 Hz ±2.5 dB
125 Hz ±2.0 dB
250 Hz ±1.9 dB
500 Hz ±1.9 dB
1 K Hz ±1.4 dB
2 K Hz ±2.6 dB
4 K Hz ±3.6 dB
8 K Hz ±5.6 dB

Remark :
The above spec. are tested under the
environment RF Field Strength less
than 3 V/M & frequency less than 30
MHz only.

2

Frequency Characteristics of A & C.
Weighting
Network A weighting :

The characteristic is simulated as "Human
Ear Listing" response. Typical, if making
the environmental sound level
measurement, always select to A
weighting.

C weighting
The characteristic is near the "FLAT"
response. Typical, it is suitable for
checking the noise of machinery (Q.C.
check) & knowing the sound pressure

level of the tested equipment.
Time Fast - t = 125 ms
weighting * "Fast" range is simulated the human ear
(Fast & Slow) response time weighting.

Slow - t = 1 s

* "Slow" range is easy to get the average

values of vibration sound level.
Data hold To freeze the measurement value.
Peak hold To keep the peak ( max. ) measurement

value.
Range selecto

r

Auto range : 30 to 130 dB.

Manual range :

2 range, 30 to 80 dB,
80 to 130 dB, 50 dB on each step,

with over & under range indicating.
Frequency 31.5 to 8,000 Hz.
Microphone Electric condenser microphone.
type
Microphone Out size, 12.7 mm DIA. ( 1/2 inch).
size

3

Calibration VR Build in external calibration VR, easy to

calibrate on 94 dB level by screw driver.

*

Calibrated via external SOUND

CALIBRATOR ( SC-942, optional ).
Calibrator B & K (Bruel & kjaer), MULTIFUNCTION

ACOUSTIC CALIBRATOR Type 4226.
Datalogger Auto 1 second to 3600 seconds
Sampling Time

@ Sampling time can set to 1 second,

Setting range but memory data may loss.

Manual Push the data logger button

once will save data one time.

@ Set the sampling time to

0 second.

@ Manual mode, can also select the

1 to 99 position ( Location ) no.

Memory Card SD memory card. 1 GB to 16 GB.
Advanced

*

Set clock time ( Year/Month/Date,Hour/Minute/ Second )

setting

*

Set sampling time

*

Auto power OFF management

*

Set beep Sound ON/OFF

*

Decimal point of SD card setting

*

SD memory card Format

*

Frequency weighting to A or C setting

Over Indication Show " - - - - ".
Data Hold Freeze the display reading.
Memory Recall Maximum & Minimum value.
Sampling Time Approx. 1 second.
of Display
Data Output RS 232/USB PC computer interface.

* Connect the optional RS232 cable

UPCB-02 will get the RS232 plug.

* Connect the optional USB cable

USB-01 will get the USB plug.

AC output AC 0.5 Vrms corresponding to each

range step.

* Output impedance : 600 ohm.

4

Power off Auto shut off saves battery life or

manual off by push button.
Operating

0 to 50 ℃.
Temperature

Operating Less than 85% R.H.
Humidity
Power Supply

*

Alkaline or heavy duty DC 1.5 V batter

y

( UM3, AA ) x 6 PCs, or equivalent.

*

DC 9V adapter input. ( AC/DC powe

r

adapter is optional ).

Power Current Normal operation ( w/o SD card save

data and LCD Backlight is OFF) :

Approx. DC 12 mA.

When SD card save the data but and

LCD Backlight is OFF) :

Approx. DC 51 mA.

*

If LCD backlight on, the powe

r

consumption will increase approx.
30 mA.

Weight 489 g/1.08 LB.
Dimension 245 x 68 x 45 mm.

( 9.6 x 2.7x 1.9 inch ).
Accessories

*

Instruction manual........................................ 1 PC

Included

*

Hard carrying case, CA-06........................... 1 PC

Optional

*

Sound calibrator ( 94 dB ), SC-941.

Accessories

*

Sound calibrator ( 94/114 dB ), SC-942.

*

Sound wind shield ball, SB-01

*

SD Card ( 2 GB )

*

USB cable, USB-01.

*

RS232 cable, UPCB-02.

*

Data Acquisition software,
SW-U801-WIN.

*

AC to DC 9V adapter.

*

Soft carrying case, CA-05A.

5

3. FRONT PANEL DESCRIPTION

Fig. 1

3-1 Display. 3-11 Calibration VR
3-2 Power Button ( ESC, Backlight Button 3-12 RS-232 output terminal
3-3 Hold Button 3-13 DC 9V adapter socket.
3-4 REC Button 3-14 Tripod Fix Nut
3-5 Range Button ( ▲ Button )

3-15 Battery Cover Screws

3-6 Fast/Slow Button/ Peak ( ▼ Button )

3-16 Stand
3-6 SET Button ( Time Button ) 3-17 Battery compartment/Cover
3-8 ENTER Button ( Logger Button ) 3-18 SD card socket
3-9 Microphone 3-19 Button
3-10 AC output terminal 3-20 Integ Time Button

6

4. MEASURING PROCEDURE

4-1 Sound Pressure Measurements (SPL

)

In SPL mode the display shows readings of

the sound pressure level.

1) Power ON the meter by pressing and holding the " Powe

r

Button " ( 3-2, Fig. 1 )for at least 1.5 seconds,
the meter's default function is " A frequency weighting ,
" SPL " " & " Fast time weighting "&" Auto range ". The
LCD display will show the Symbol " A.SPL, Fast , Auto ".

2)

Frequency weighting select
How to select the frequency weighting ( A or C), the
procedures please refer to chapter 7-7 page 21 .

Note :
a.

The characteristic table of A,C weighting, pleas

e

ref. page 25.

b.

The characteristic of A weighting is simulated as the

" Human Ear Listening " response.

Typically always select the A weighting when make

s

environmental sound level measurement.

c. The C weighting characteristic is near the " FLAT

"

response. Typically it is suitable for checking the
noise of machinery ( Q.C. check ) & knowing the
real sound level of the tested equipment.

3)

Determine proper measuring range by pressing and holding
the " Range Button " ( 3-5, Fig. 1 ) for at least 1.5 seconds.
until the desired range is shown (AUTO , 30 - 80 , 80 - 130db ,
AUTO) reading in the center of the range. If dashes appear
on the display select a new range , After power on the default
range is " Auto range " In the same time the LCD display
will show the text of " Auto " Under the auto range.

7

pressing and holding the " Range Button "( 3-5, Fig. 1 ) again
range will enter to the manual range ( range 1,range 2 )
and auto range in sequence ,There are still 2 manual ranges.
for your choice :

* Manual range 1 , 30 - 80 dB range

:

Display will show the text of " 30 - 80 ".

* Manual range 2 , 80 - 130 dB range

:

Display will show the text of " 80 - 130 ".

4)

According to various measuring sound source, select the
Time Weighting ( Fast or Slow or PEAK Fast ) by pressing and
holding the "Function ( Time Weighting Button ) " ( 3-7, Fig. 1 ).

Note :
a.

If select the function of " Fast " time weighting, th

e

display will show the unit of " FAST".

b. If select the function of " Slow " time weighting, th

e

display will show the unit of " SLOW ".

c. If select the function of " PEAK FAST " time weighting, th

e

display will show the unit of " PEAK FAST " and will show

maxmun reading .

4-2 Integrating Sound Level Meter Measurements (Leq

)

In the Leq mode the display will shows the integrated

level for the run period readings.

1) Power ON the meter by pressing and holding the " Powe

r

Button " ( 3-2, Fig. 1 )for at least 1.5 seconds,
the meter's default function is " A frequency weighting ,
" SPL " " & " Fast time weighting "&" Auto range ". The
LCD display will show the Symbol " A.SPL, Fast , Auto ".

2)

Select the Leq

mode by pressing and holding the

" MODEL button" ( 3-20 Fig 1 ) select to the Leq MODEL .

8

3) Frequency weighting select
How to select the frequency weighting ( A or C), the procedures
please refer to chapter 7-7 page 21 .

4)

According to various measuring sound source, select the
Time Weighting ( Fast or Slow or PEAK Fast ) by pressing and
holding the "Function ( Time Weighting Button ) " ( 3-7, Fig. 1 ).

5)

Select the desired Run Time.,There are 13 preset time settings
available .

1 second 3 second 10 second 30 second 1 minute
5 minutes 8 minute 10 minutes 15 minute

s

30 minutes

1 hour 8 hour 24 hour

Change the run time by pressing the" INTEG TIME button"
( 3-20 Fig .1 ) once, The run time will appear in the LCD
below , then Press the " ▲ buttom"( 3-5 Fig . 1 ) o r "▼ buttom"

( 3-5 Fig . 1 ) button to select the preset time setting.

1. Press" button"( 3-19 Fig . 1 ) once to begin measuring,
The run time counter will zero and begin counting While
running the meter will Show " ► " Symbol at the display.

2. When the “ “ button"( 3-19 Fig . 1 ) is pressed again,
the measurement will pause and the display will show

“

‖”,

At the same time " ► " Symbol Disappear.

3. When the “ “ key is pressed again, the
measurement will continue , At the same time "‖" Symbol

Disappear and the display will show " ► "Symbol, At a
preset time interval has expired, and will display " ■ " Symbol ,

and Leq recording interval, the instrument will automatically
stop.

9

6) When Integrating Time set to zero ,push " "( 3-19 Fig . 1)
buttom once, meter to begin integra measurement,At the same
time meter will Show " ►

" Symbol at the display The run
time counter will zero and begin counting While running the
meter will Show " ► "Symbol at the display.
When the “ “ button"( 3-19 Fig . 1 ) is pressed again,
the measurement and Integrating time counter will automatically
stop , and the display will show and hold Integrating
reading and show " ■ " Symbol, at the same time " ► "

Symbol Disappear.

4-3 Data Hol

d

During the measurement, press the " Hold Button " ( 3-3,
Fig. 1 ) once will hold the measured value & the LCD will
display a " HOLD " symbol.
Press the " Hold Button " once again will release the data
hold function.

4-3 Data Record ( Max., Min. reading

)

1) The data record function records the maximum and
minimum readings. Press the " REC Button " ( 3-4, Fig.1 )
once to start the Data Record function and there
will be a " REC " symbol on the display.

2) With the " REC " symbol on the display :
a)

Press the " REC Button " ( 3-4, Fig. 1 ) once, the
" REC MAX " symbol along with the maximum value
will appear on the display.
If intend to delete the maximum value, just press
the " Hold Button " ( 3-3, Fig. 1 ) once, the display
will show the " REC " symbol only & execute the
memory function continuously.

10

b) Press the " REC Button " ( 3-4, Fig. 1 ) again, the

" REC MIN " symbol along with the minimum value
will appear on the display.
If intend to delete the minimum value, just press the
" Hold Button " ( 3-3, Fig. 1 ) once, the display will
show the " REC " symbol only & execute the
memory function continuously.

c)

To exit the memory record function, just press the
" REC " button > 2 seconds at least. The display will
revert to the current reading.

4-4 LCD Backlight ON/OF

F

After power ON, the " LCD Backlight " will light
automatically. During the measurement, press the
" Backlight Button " ( 3-2, Fig. 1 ) once will turn OFF the
" LCD Backlight ".
Press the " Backlight Button " once again will turn ON the
" LCD Backlight " again.

11

5. DATALOGGER

5-1 Preparation before execute datalogger functio

n

a. Insert the SD card
Prepare a " SD memory card " ( 1 GB to 16 GB, optional ),
insert the SD card into the " SD card socket " ( 3-18, Fig. 1).
The front panel of the SD card should face against the
the down case.

b. SD card Format
If SD card just the first time use into the meter, it
recommend to make the " SD card Format " at first. ,
please refer chapter 7-6 ( page 21 ).

c. Time setting
If the meter is used at first time, it should to adjust the
clock time exactly, please refer chapter 7-1 ( page 18 ).

d. Decimal format setting

The numerical data structure of SD card is
default used the " . " as the decimal, for
example "20.6" "1000.53" . But in certain
countries ( Europe ...) is used the " , " as the
decimal point, for example " 20, 6 "
"1000,53". Under such situation, it should
change the Decimal character at first, details
of setting the Decimal point, refer to Chapter
7-5, page 20.

5-2 Auto Datalogger ( Set sampling time

≧

1 second )

a. Start the datalogger

Press the " REC Button ( 3-4, Fig. 1 ) once , the LCD will
show the text " REC ", then press the " Logger Button " (
3-8, Fig. 1 ), the " REC " will flashing , at the same time

12

the measuring data along the time information will be
saved into the memory circuit.

The Display will show also show text " LOGGER "
when the data save into the memory circuit.

Remark :
How to set the sampling time, refer to Chapter 7-2,
page 19.

b. Pause the datalogger

During execute the Datalogger function , if press the
" Logger Button " ( 3-8, Fig. 1 ) once will pause the
Datalogger function ( stop to save the measuring data
into the memory circuit temporally ). In the same time
the text of " REC " will stop flashing.

Remark :
If press the " Logger Button " ( 3-8, Fig. 1 ) once agai

n

will execute the Datalogger again, the text of " REC " wil

l

flashing .

c. Finish the Datalogger

During pause the Datalogger, press the " REC Button "
( 3-4, Fig. 1) continuously at least two seconds, the " REC "
indicator will be disappeared and finish the Datalogger.

Remark :
When the battery is under the low battery conditio

n

( show the low battery indicator ), the Datalogge

r

function is disable.

13

5-3 Manual Datalogger ( Set sampling time =

0

second )

a. Set sampling time is to 0 second

Press the " REC Button ( 3-4, Fig. 1 ) once , the LCD will
show the text " REC ", then press the " Logger Button "
( 3-8, Fig. 1 ) once, the " REC " will flashing once,
at the same time the measuring data along the time
information and the Position no. will be saved into the
memory circuit.

Remark :
*

Lower Display will show the Position/Location no.
( P1, P2... P99 ) .

*

During execute the Manual Datalogger,
press the " SET Button " ( 3-7, Fig. 1 ) once, then us

e

the "

▲

Button " ( 3-5, Fig. 1) or "

▼

Button " ( 3-6,

Fig. 1 ) to set the measuring position ( 1 to 99, fo

r

example room 1 to room 99 ) to identify th

e

measurement location. After finish the adjustmen

t

location no., press the " Enter Button " to entry.

b. Finish the Datalogger

Press the " REC Button " ( 3-4, Fig. 1) continuously at
least two seconds, the " REC " indication will be
disappeared and finish the Datalogger.

5-4 Check time and sampling time informatio

n

During the measurement if press " Time Button "
( 3-5, Fig. 1 ) ones, the LCD display will
present the time and sampling time information of Year/Month,
Date/Hour, Minute/Second, and sampling time informationin
in second unit.

14

5-5 SD Card Data structur

e

1) When the SD card is used into the meter, the SD card
When the first time, the SD card is used into the meter,
the SD card will generate a folder :

SLA01

2) If the first time to execute the Datalogger,
under the route SLA01\, will generate a new
file name SLA01001.XLS.
After exist the Datalogger, then execute again,
the data will save to the SLA01001.XLS until
Data column reach to 30,000 columns, then
will generate a new file, for example SLA01002.XLS

3) Under the folder SLA01\, if the total files more
than 99 files, will generate anew route, such as

SLA02\ ........

4) The file's route structure :
SLA01\

SLA01001.XLS
SLA01002.XLS

.....................

SLA01099.XLS

SLA02\

SLA02001.XLS
SLA02002.XLS

.....................

SLA02099.XLS

SLAXX\

.....................

.....................

Remark : XX : Max. value is 10.

15

6. Saving data from the SD card

to the computer ( EXCEL software )

1) After execute the Data Logger function, take away th

e

SD card out from the " SD card socket " ( 3-18, Fig. 1 ).

2) Plug in the SD card into the Computer's SD card slo

t

( if your computer build in this installation ) or
insert the SD card into the " SD card adapter ". then
connect the " SD card adapter " into the computer.

3) Power ON the computer and run the " EXCEL software ".
Down load the saving data file ( for example the fil

e

name : SLA01001.XLS, SLA01002.XLS ) from the SD
card to the computer. The saving data will present int

o

the EXCEL software screen ( for example as following
EXCEL data screens ) , then user can use those EXCE

L

data to make the further Data or Graphic analysi

s

usefully.

EXCEL data screen ( for example )

16

EXCEL graphic screen ( for example

)

17

7. ADVANCED SETTING

Under do not execute the Datalogger function,
press the " SET Button " ( 3-7, Fig. 1 ) continuously at
least 1.5 seconds will enter the " Advanced Setting " mode.
then press the " SET Button " (3-7, Fig. 1 ) once a while
in sequence to select the six main function, the lower
display will show :

DATA…… Set clock time ( Year/Month/Date, Hour/Minute/

Second )

SP-T......... Set sampling time ( Hour/Minute/Second )

POFF....... Auto power OFF management

BEEP.......

.

Set beeper sound ON/OFF

DEC..........Set SD card Decimal character

SD- F........ SD memory card Format

A ………. Select the Frequency weighting to A or C

During execute the " Advanced Setting " function

,

if press " HOLD Button " ( 3-2, Fig. 1 ) once will exit
the " Advanced Setting " function, the LCD will
return to normal screen.

7-1 Set clock time ( Year/Month/Date,
Hour/Minute/ Second

)

When the lower display show " DATE "

1)

Use the " ▲ Button " ( 3-5, Fig. 1 ) or " ▼

Button "

( 3-6, Fig. 1 ) to adjust the value ( Setting start from
Year value ). After the desired value is set, press the
" Enter Button " ( 3-8, Fig. 1 ) once will going to
next value adjustment ( for example, first setting
value is Year then next to adjust Month, Date, Hour,
Minute, Second value ).

18

2) After set all the time value ( Year, Month, Date, Hour,
Minute, Second ),
the screen will jump to " SD card Decimal character "
setting screen ( Chapter 7-2 ).

Remark

:

After the time value is setting, the internal clock wil

l

run precisely even Power is off ( The battery is unde

r

normal condition, no low battery condition ).

7-2 Set sampling time ( seconds )

When the lower display show " SP-t "

1)

Use the " ▲ Button " ( 3-5, Fig. 1 ) or " ▼ Button " (
3-6, Fig. 1 ) to adjust the value ( 0, 1, 2, 5, 10, 30,60,

120, 300, 600, 1800,3600 seconds ).

Remark

:

If select the sampling time to " 0 second ", it is ready
for manual Datalogger.

2)

After the Sampling value is selected, press the
" Enter Button " ( 3-8, Fig. 1 ) will save the setting
function with default.

7-3 Auto power OFF managemen

t

When the lower display show " POFF "

1)

Use the " ▲ Button " ( 3-5, Fig. 1 ) or " ▼

Button "

( 3-6, Fig. 1 ) to select the upper value to " YES " or
" NO ".

YES - Auto Power Off management will enable.
NO - Auto Power Off management will disable.

2)

After select the upper text to " YES " or " NO ", press the
" Enter Button " ( 3-8, Fig. 1 ) will save the setting
function with default.

19

7-4 Set beeper sound ON/OF

F

When the lower display show " BEEP "

1)

Use the " ▲ Button " ( 3-5, Fig. 1 ) or " ▼

Button "

( 3-6, Fig. 1 ) to select the upper value to " YES " or
" NO ".

YES - Meter's beep sound will be ON with default.
NO - Meter's beep sound will be OFF with default.
is power ON.

2)

After select the upper text to " YES " or " NO ", press the
" Enter Button " ( 3-8, Fig. 1 ) will save the setting
function with default.

Remark

:

After execute the datalogger function, the buzzer soun

d

will off automatically to prevent any interference of
the measurement.

7-5 Decimal point of SD card settin

g

The numerical data structure of SD card is default used
the " . " as the decimal, for example "20.6" "1000.53" .
But in certain countries ( Europe ...) is used the " , " as
the decimal point, for example " 20,6 " "1000,53".
Under such situation, it should change the Decimal
character at first.

When the lower display show " DEC "

1)

Use the " ▲ Button " ( 3-5, Fig. 1 ) or " ▼

Button "

( 3-6, Fig. 1 ) to select the upper value to " USA " or
" EURO ".

20

USA - Use " . " as the Decimal point with default.
EURO - Use " , " as the Decimal point with default.

2)

After select the upper text to " USA " or " EURO ",
press the " Enter Button " ( 3-8, Fig. 1 ) will save the
setting function with default.

7-6 SD memory card Forma

t

When the lower display show " SD F "

1)

Use the " ▲ Button " ( 3-5, Fig. 1 ) or " ▼ Button " (
3-6, Fig. 1 ) to select the upper value to "YES " or

" NO ".

YES - Intend to format the SD memory card
NO - Not execute the SD memory card forma

t

2) If select the upper to " YES ", press the " Enter Button
" ( 3-8, Fig. 1 ) once again, the Display will show text
" YES Ent " to confirm again, if make sure to do the
SD memory card format, then press " Enter Button "
once will format the SD memory clear all the existing
data that already saving into the SD card.

7-7 Frequency weighting to A or C settin

g

When the lower display show " A "

1)

Use the " ▲ Button " ( 3-5, Fig. 1 ) or " ▼

Button "

( 3-6, Fig. 1 ) to select the upper value to " A " or
" C ".

A - A Frequency weighting selection.
C - C Frequency weighting selection.

21

2) After select the upper text to " A " or " C ",
press the " Enter Button " ( 3-8, Fig. 1 ) will save the
setting function with default.

Note :

a. The characteristic table of A, C weighting, please

ref. page 25.

b.

The characteristic of A weighting is simulated a

s

the " Human Ear Listening " response.
Typically always select the A weighting when make

s

environmental sound level measurement.

c. The C weighting characteristic is near the " FLAT

"

response. Typically it is suitable for checking the
noise of machinery ( Q.C. check ) & knowing the
real sound level of the tested equipment.

8. POWER SUPPLY from DC ADAPTER

The meter also can supply the power supply from the
DC 9V Power Adapter ( optional ). Insert the plug of
Power Adapter into " DC 9V Power Adapter Input Socket "
( 3-13, Fig. 1 ). The meter will permanent power ON
when use the DC ADAPTER power supply ( The power
Button function is disable ).

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9. BATTERY REPLACEMENT

1) When the left corner of LCD display show " ", it
is necessary to replace the battery. However, in-spec.
measurement may still be made for several hours after
low battery indicator appears before the instrument
become inaccurate.

2) Loose the " Battery Cover Screws " ( 3-15, Fig. 1 )
and take away the " Battery Cover " ( 3-17, Fig. 1 )
from the instrument and remove the battery.

3)

Replace with DC 1.5 V battery ( UM3, AA,
Alkaline/heavy duty ) x 6 PCs, and reinstate the cover.

4) Make sure the battery cover is secured after changing
the battery.

10. RS232 PC SERIAL INTERFACE

The instrument has RS232 PC serial interface via a 3.5
mm terminal ( 3-12, Fig. 1 ).

The data output is a 16 digit stream which can be
utilized for user's specific application.

A RS232 lead with the following connection will be
required to link the instrument with the PC serial port.

Meter PC

(9W 'D" Connector)

Center Pin.................................... Pin 4

(3.5 mm jack plug)

Ground/shield..................................

.

Pin 2

2.2 K
resisto

r

Pin 5

23

The 16 digits data stream will be displayed in the

following format :

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

Each digit indicates the following status :

D15 Start Word
D14 4
D13 When send the upper display data = 1

When send the lower display data = 2

D12, D11 Annunciator for Displa

y

dB = 17

D10 Polarity

0 = Positive 1 = Negative

D9 Decimal Point(DP), position from right to the

left
0 = No DP, 1= 1 DP, 2 = 2 DP, 3 = 3 DP

D8 to D1 Display reading, D1 = LSD, D8 = MSD

For example :

If the display reading is 1234, then D8 to
D1 is : 00001234

D0 End Word

RS232 FORMAT : 9600, N, 8, 1

Baud rate 9600
Parity No parity
Data bit no. 8 Data bits
Stop bit 1 Stop bit

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11. CALIBRATION

1) Prepare the optional " SOUND CALIBRATOR ", such as
" SC-941 " or " SC-942 " ( set range to 94.0 dB ). Power
on the Sound Calibrator & plug calibrator output socket
into the " Microphone " head ( 3-9, Fig. 1 ) of the
Sound Level meter.

2)

Select manual range to "80- 130 dB ".

3) Select " Time Weighting " at " Fast " position.

4) Select " A " weighting.

5) Adjust the " Calibration VR " ( 3-11, Fig. 1 ) carefully
with a " - " screw driver until the display reading value
within " 94 +/- 0.2 " dB.

12. FREQUENCY WEIGHTING
CHARACTERISTICS OF A & C
NETWORKS

Frequency A Weighting C Weighting Tolerance

Charac. Charac. ( IEC 61672

Class 2 )

31.5 Hz -39.4 dB -3 dB ±3.5 dB
63 Hz -26.2 dB -0.8 dB ±2.5 dB
125 Hz -16.1 dB -0.2 dB ±2.0 dB
250 Hz -8.6 dB 0 dB ±1.9 dB
500 Hz -3.2 dB 0 dB ±1.9 dB
1 KHz 0 dB 0 dB ±1.4 dB
2 KHz +1.2 dB -0.2 dB ±2.6 dB
4 KHz +1 dB -0.8 dB ±3.6 dB
8 KHz -1.1 dB -3 dB ±5.6 dB

25

13. TIME WEIGHTING ( F/S )
CHARACTERISTICS

` Max. response Tolerance
Charac. ref. continuous ( IEC 61672 Class 2 )

signal
F ( Fast ) - 1.0 dB + 1.0 dB , - 2.0 dB
S ( Slow ) - 4.1 dB ±2.0 dB

* Test under signal on 1,000 Hz/94 dB.

14. PATENT

The meter ( SD card structure ) already
get patent or patent pending in following
countries :

Germany Nr. 20 2008 016 337.4
JAPAN 3151214
TAIWAN M 358970

M 359043
CHINA ZL 2008 2 0189918.5

ZL 2008 2 0189917.0
USA Patent pending

26

MRC.24.2016