Iso-Tech SLA-1358 Instruction Manual

ISO-TECH

INSTRUCTION MANUAL

Sound Analyser

Real Time 1/1 & 1/3 Octave band Analysis

SLA-1358

CONTENTS

Title Page

I. SAFETY INFORMATION....................................... 1

II. GENERAL INFORMATION & FEATURES ........... 2

III. SPECIFICATIONS.................................................. 2

IV. CONTROLS AND FUNCTIONS ............................ 5

4-1 Parts description...................................................5

4-2 Operation keys .....................................................7

4-3 Measurement screen..........................................10

V. CALIBRATION PROCEDURES .......................... 11

VI. MEASUREMENT PREPARATION......................12

VII. SETTING THE DATE AND TIME ........................12

VIII. SOUND PRESSURE LEVEL MEASUREMENT. 13

8-1 Technical notes...................................................13

8-2 Instantaneous sound pressure level measurement

, LC, LP)...........................................................14

(L

A

8-3 Leq and LE measurement ....................................16

IX. MEMORY FUNCTION.......................................... 18

9-1 Manual storing data in memory (1024 data sets)18

9-2 Reading from memory........................................20

9-3 Automatic data storage in memory .....................21

9-4 Erase memory data ............................................23

I. SAFETY INFORMATION

q Read the following safety information carefully before

attempting to operate or service the meter.

q Use the meter only as specified in this manual, otherwise the

protection provided by the meter and general operation may
be impaired.

q Environmental conditions

 Altitude up to 2000 metres

 Relative humidity 90% max.

 Ambient operating temperature 0 〜 40℃

q Maintenance & Cleaning

 Repairs or servicing not covered in this manual should

only be performed by qualified personnel.

 Periodically wipe the case with a dry cloth. Do not use

abrasives or solvents on this instrument.

q Safety symbols

Complies with the EMC directive.

1

II. GENERAL INFORMATION & FEATURES

The SLA 1358 meter allows digital 1/1-octave and 1/3-octave
analysis in real time.

q Five measured parameters SPL (Sound Pressure Level), Leq

(Equivalent Continuous Sound Pressure Level), LE (Sound
Exposure Level), Lmax (Maximum Sound Pressure Level),
Lmin (Minimum Sound Pressure Level)

q RS-232 interface for PC connection

q Data Logger function

q Real time clock with calendar

q Both AC and DC signal output is available for level or graphic

recorder

q Auto-Ranging for SPL function

III. SPECIFICATIONS

q Standard applied : IEC 60651 type2, 60804 type 2, ANSI S1.4

type2, IEC 1260 (1995).

q Display : Backlit LCD, 160×160 dots.

Sound level meter mode

Numeric display : 4 digits, update rate 0.5S,
resolution 0.1 dB.
Bar graph display :100dB range, update rate

0.125S, resolution 1dB.

Frequency analysis mode

Numeric display : 4 digits, update rate 0.5S,
resolution 0.1dB.
Bar graph display : 70dB range, update rate

0.125S, resolution 1 dB.

2

q Accuracy : ±1.5dB (ref 94dB @1kHz)

q Measurement Frequency range : 25Hz – 10KHz

q Dynamic range : 100dB (Sound level meter mode)

70dB (Frequency analysis mode)

q Measurement range : 30dB – 130dB

q Sound Pressure Level range:

Sound level meter mode (display range 100dB) :

30 – 130dB

Frequency analysis mode (display range 70dB) :

20–90dB, 30–100dB, 40–110dB, 50–120dB, 60–130dB

q Frequency weighting : A, C, P (Flat)

q Time weighting : Fast, Slow

q Microphone : 1/2 inch electret condenser microphone.

q Display warning indicator :

OVER indicator (Input signal over the upper limit)
UNDER indicator (Input signal under the lower limit)

q Warm-up time : Less than 20min

q Memory capacity : Manual store block and auto store block

(separate).

Store mode

Mode

Manual Auto

Sound level meter 1024 data sets 10000 data sets

1/1-octave analysis 1024 data sets 6140 data sets

1/3-octave analysis 1024 data sets 3070 data sets

3

q AC output : 2 Vrms at FS (full scale).

output impedance approx. 600Ω.

q DC output : 10mV/dB.

output impedance approx. 100Ω.

q Power : Qty 4, C size 1.5V (LR14) alkaline batteries.

External DC power supply : 6 Vdc, 1A.

q Battery life : Approx. 2 hours continuous use

q Operating Temperature/Humidity : 0℃ to +40℃,10 to 90%RH.

q Storage Temperature/Humidity : -10℃ to +60℃,10 to 75%RH.

(battery removal)

q Dimensions & Weight : 34.5(H) × 10(W) × 6(D) cm

Approx. 950g (including batteries).

q Accessories : Instruction manual, 4 x alkaline batteries, hard

carry case, CD-ROM software, RS-232 cable, 9
pin to 25 pin gender changer, adjustment
screwdriver, windscreen, 3.5f plug, AC
adapter.

4

IV. CONTROLS AND FUNCTIONS

4-1 Parts description

FAST

L

A W

100

[ 1 / 3 OCT ] 01 / 06 / 19 14:26:39

65.2 dB

dB
80

60

40

20

2k

31.5Hz 500125

W8k L

N
O

T
H
G

I

F

L
F
O

T

S

A

R

T

N

O

C

C

T

A

U

P

T

U

C

O

D

V

6

C

D

L

A

C

N

R

O

E

W

O

F

P

F
O

SOUND ANALYZER
1/1 & 1/3 OCTAVE BAND
IEC 651 IEC 804 TYPE 2
IEC 1260 CLASS2
ACCURACY : ¡ Ó1.5dB

IEC LR14 1.5V X 4

1. Windscreen
The windscreen should be used with the meter if operating in
conditions where wind speed exceeds 10m/sec.

2. Microphone

3. Display

4. Operation keys

5

5. Power switch.

This sliding switch serves to turn the unit on and off.

6. Calibration adjustment knob.
Used to carry out manual calibration, using the supplied
adjustment screwdriver.

7. DC 6V jack.
For use with AC power adapter.

8. DC output jack.
A DC signal corresponding to the sound pressure level is
available at this output.

9. AC output jack.
An AC signal corresponding to the sound pressure is available
at this output.

10. LCD contrast adjust knob.

Used to adjust the display contrast (using the supplied
adjustment screwdriver).

11. LCD backlight switch.

Used to turn the display backlight on and off.

12. Hand strap.

The strap should be used to safely carry the unit during field
operation.

13. RS-232 interface connector.

Used for input and output of control signals and
measurement data.

14. Battery compartment

15. Tripod mounting screw.

6

4-2 Operation keys

a.) MODE key

Calls up the various processing results on the
display.

Display options are sound pressure level (L),
equivalent continuous sound pressure level (Leq),
sound exposure level (LE), maximum sound pressure
level (Lmax), and minimum sound pressure level
(Lmin).

b.) FREQ WGHT key

Selects the frequency weighting characteristic.
Available settings are “A” weighting (A), “C” weighting
(C), and flat frequency response (P).

c.) TIME CONST key

Selects the time weighting. Available settings are
“FAST” and “SLOW”.

7

d.)

5LEVEL6
Used to select the sound pressure level ranges on 1/1 and 1/3
octave band frequency analysis mode. (20~90dB, 30~100dB,
40~110dB, 50~120dB and 60~130dB, total 5 ranges)

e.)

SLM/ 1/1/ 1/3 key

This key switches the operation mode between sound
level meter (SLM), 1/1-octave frequency analysis (1/1),
and 1/3-octave frequency analysis (1/3).

f.)

MEAS TIME key

 Sets the Leq, LE, Lmax and Lmin measurement time :

24hà1sà3sà10sà30sà1mà5mà8mà10mà15mà
30mà1hà8h



2nd + MEAS TIME : Enter to setting the date

and time mode.

g.) MEMORY key



Enter to memory mode.



2nd + MEMORY : Enter to data record interval

time setting : 0 (no record)

à1s à3sà10s

à30sà1mà5mà8mà10mà15mà 30mà1hà62.5ms

h.) ENTER key

Store the new date and time and start the time clock.

i.) 3Cursor4 key

 Serve to move the octave frequency band marker during

frequency analysis.

 2nd+ 3Cursor4 : In recall mode to select the memory

address in which to store the measurement data.

j.) START/STOP key

8

Press to start and to terminate the Leq, LE, Lmax and Lmin

sound pressure level measurement.

k.) PAUSE/CONT key

Used to temporarily pause measurement ( display ) or

resume (4display ).

l.) 2nd key

Press to shift key to second function.

m.) STORE key

In manual memory mode, stores the measured data into

the memory.

n.) RECALL key

In manual memory mode, recalls the stored memory data.

o.) STORE + RECALL key (Erase memory data)

Turn off the meter, press and hold down STORE and
RECALL keys. Turn on the meter whilst holding the keys
until the display shows “All memory is erased”.

9

4-3 Measurement screen

1. Sound pressure level measurement screen

FAST

A

L

dB

30 80

130

[ SLM ] 01 / 07 / 27 14:26:39

2. 1/1-octave analysis screen
The bar display on the LCD represents the 1/1-octave analysis
result. From left, the bars correspond to 31.5, 63, 125, 250,
500, 1k, 2k, 4k, 8kHz. To read the levels at these frequencies,
use the 3Cursor4 key to move the cursor to the desired
point. The frequency and level are then shown on the upper
part of the screen.

FAST

AL

dB

100

90
80
70
60
50
40
30

31.5 125Hz

[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39

2k Hz

68.4 dB

8k2k500

L W

10

3. 1/3-octave analysis screen
The bar graph shape on the display represents the 1/3-octave
analysis result. From left, the bars correspond to 25, 31.5, 40,
50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630, 800,
1k, 1.25k, 1.6k, 2k, 2.5k, 3.15k, 4k, 5k, 6.3k, 8k, 10kHz. To
read the levels at these frequencies, use the 3Cursor4 key
to move the cursor to the desired point. The frequency and
level are then shown at the top of the screen.

FAST

A

L W 75.2 dB

dB

100

90
80
70
60
50
40
30

31.5Hz

2k500125 8k L W

[ 1 / 3 OCT ] 01 / 07/ 27 14:26:39

V. CALIBRATION PROCEDURES

Using a standard acoustic calibrator such as the ISO-TECH SLC

1356

1. Make the following switch settings.
Display : SLM (LA)
Time weighting : FAST

2. Insert the microphone housing carefully into
the insertion hole of the calibrator.

3. Turn on the calibrator and adjust the CAL
potentiometer of the unit so that the display
indicates the desired level.

Recommended re-calibration cycle : 1 year.

Caution : Ambient sources of noise or vibration

can cause a false calibration.

FAST

A

L

30

80dB130

[ SLM ] 01 / 06 / 19 1 4:26:39

11

VI. MEASUREMENT PREPARATION

1. Battery installation.

Remove the battery cover on the back of the meter and insert

batteries (4 x 1.5V size C).

Note : Take care to observe battery polarity.

2. Battery replacement.

When the battery voltage drops below the operating voltage,
LBATT appears and flashes on the display. When it appears,
the batteries should be replaced.

3. AC adapter connection.

VII. SETTING THE DATE AND TIME

Date and time information is stored with each record you save.
Therefore, it is important to make sure this information is correct.
Set the date and time as described below :

1. Press 2nd key once, then press MEAS TIME key to enter
the date and time mode.
The display screen in the second location will flash.

2. Press 5LEVEL6 key to set the required numbers.

3. Press 3Cursor4 key to move between different fields &
locations (year/month/day/hour/minute/second)

4. Press 5LEVEL6 key to set the number.

5. When the setting is correct, press the ENTER key to exit
this mode.

12

VIII. SOUND PRESSURE LEVEL MEASUREMENT

8-1 Technical notes

1. The decibel (dB).
The range over which the human ear responds to sound
pressure (noise) is extremely large ; 20mPa (the threshold of
hearing) to 100 Pa (the threshold of pain). The measurement
of sound pressure is made manageable by use of the decibel,
which is logarithmic. This is good for ease of reference,
however it means that decibels are not linear and so can not
be added together. A simple rule is that doubling the noise
causes the level to rise by 3dB.

2. SLM - sound level meter.

Instantaneous sound pressure level (SPL) is used for spot
checks to establish instantaneous noise levels that might be
of concern and is defined by the logarithmic equation :

SPL (in dB) : 20 log

10

0P

Where P = rms measured sound pressure level

P0 = rms reference sound pressure level (deemed to

be 20m Pa)

3. Leq-level equivalent (continuous).

Leq is used to assess the rms average noise level over a
preset period of time, often the starting point of a noise
assessment.
To make an Leq measurement the period of time over which
it is to be made must be selected. The longer the period of
measurement, the more accurate the Leq reading, a typical
period used is 8 hours (the length of a working day).

4. LE – Sound exposure level.
LE measurements are almost identical to Leq measurements

13

P

but compressed in to 1 second. This allows the total sound
energy of an event, such as train passing a platform, to be
evaluated. Another event, such as the next train, which lasts
for a different amount of time can be measured in the same
way. The two readings can be compared to assess how
much total noise the passengers standing at the platform
were exposed to by each train. To make an L

measurement

E

either a preset time period must be selected on the
instrument, or the
PAUST/CONT

key must be used to stop and start

measurement of a specific event.

8-2 Instantaneous sound pressure level measurement (LA, LC, LP).

To perform a measurement, carry out the following steps.

1. Set the power switch to ON and wait until the measurement
screen appears.

ID No: 00001358 Ver: 0.10

SOUND LEVEL METER
1/1 & 1/3 Octave Band
Real-Time Analyzer

Self-Testing...

FAST

L

A

30 80

[ SLM ] 01 / 07 / 27 14:26:39

dB

130

2. Press the SLM/ 1/1/ 1/3 key to select desired SLM, 1/1 or
1/3 octave band sound pressure level measurement screen.

14

FAST

A

L

dB

100

90
80
70
60
50
40
30

500

125Hz 31.5

75.2 dBW

8k L W2k

[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39

FAST

A

L W 75.2 dB

dB

100

90
80
70
60
50
40
30

31.5Hz

2k500125 8k L W

[ 1 / 3 OCT ] 01 / 07/ 27 14:26:39

3. Use the FREQ WGHT key to select the desired LA , LC or L
frequency weighting setting.

4. Use the TIME CONST key to select the desired FAST or
SLOW time constant setting. Normally, the “FAST” setting
should be used.

5. Use the 5LEVEL6 key to select the level range . Choose
a setting in which the “OVER” and “UNDER” indications do
not appear. In SLM mode, the dynamic range is 30~130dB,
so the 5LEVEL6 key is not activated.

P

FAST

100

A

L

dB

90
80
70
60
50
40
30

125Hz 31.5

500

75.2 dBW

[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39

15

WL8k2k

8-3 Leq and LE measurement

To perform a measurement, carry out the following steps.

1. Set the power switch to ON and wait until the measurement

screen appears.

2. Press the MEAS TIME key, setting the preset measurement

time for a fixed time period (know as the integral time), after
which measurement automatically stops.

There are 13 preset time settings available :

· 1s · 10min

· 3s · 15min

· 10s · 30min

· 30s · 1h

· 1min · 8h

· 5min · 24h

· 8min

Note : The setting will wrap around from 24h to 1s.

FAST

A W 75.2 dB

L

dB

100

90
80
70
60
50
40
30

Hz 31.5 125 500 2k WL8k

[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39

16

3. Use the SLM/ 1/1/ 1/3 key to select desired SLM, 1/1 or 1/3

octave band sound pressure level measurement screen.

4. Use the FREQ WGHT key to select the desired LA, LC or L

P

frequency weighting setting.

5. Use the TIME CONST key to select the desired FAST or

SLOW time constant setting. Normally, the “FAST” setting
should be used.

6. Use the 5LEVEL6 key to select the level range. Choose a

setting in which the “OVER” and “UNDER” indications do not
appear. In SLM mode, the dynamic range is 30~130dB, so the
5LEVEL6

key is not activated.

7. Press the START/STOP key. The “4” mark on the display

and the equivalent continuous sound pressure level
measurement begins.

8. In any of the following measurement modes; “4measuring”, “

pause ” or “

■ terminate ”; the MODE key can be used to

select and view any other parameter L, Leq, LE, Lmax or Lmin.

9. When the measurement time set in step 2 has elapsed, the

meter will automatically stop taking measurements.

10. If you need to stop measuring earlier than originally stated,

press the PAUSE/CONT key to pause measuring. The “ ”
mark will appear on the display. Press PAUSE/CONT key
again to continue taking measurements.

11. Press the START/STOP key to stop measuring. The “ ■ ”

symbol will appear on the display.

12. Press the MODE key to display the L

Aeq

, L

or other

AE

parameter value.

Note : In this measurement mode, the frequency weighting,

time weighting and SLM/ 1/1/ 1/3 modes cannot be
changed.

17

IX. MEMORY FUNCTION

The SLA 1358 incorporates a memory that allows manual and
automatic storing of measured data. Stored measurement results
can be displayed by pressing the RECALL key.

MANU (manual store):
Measured data and processing results can be stored manually

by the operator.

AUTO (automatic store)
Automatically stores data at a required pre-set time interval.

9-1 Manual storing data in memory (1024 data sets)

1. Switch the meter on.

2. Use the SLM/ 1/1/ 1/3 key to select the desired

measurement parameter (SLM, 1/1 or 1/3 octave band sound
pressure level measurement screen).

3. Press MEMORY key, enter to memory mode, display M [0001]

first data record memory address number.

FAST

L

dB

100

90
80
70
60
50
40
30

31.5Hz

[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39

WA 75.2 dB

2k500125 8k L W

4. Press the STORE key, one set of data is stored in the [0001]

memory address. The address counter is increased by one .

18

By repeating this procedure, more data can be stored in
memory.

5. Press MEMORY key again to exit the memory mode.

19

9-2 Reading from memory

1. Press MEMORY key, enter memory mode, display M

[****].

2. Press RECALL key, display R [****] record number and data

value. If no data records are stored in the memory, the RECALL
key will not activate.

FAST

L

dB

100

90
80
70
60
50
40
30

31.5Hz

[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39

WA 75.2 dB

2k500125 8k L W

3. Press 2nd key, the 2ND annunciator at the upper left of the

screen will display.

4. Press 3Cursor4 key to select the memory address from

which you want to display data.

5. If in the 1/1 or 1/3 octave band screen, Press 2nd key to

remove 2nd annunciator, then press the 3Cursor4 key.

The frequency and level display at the upper of the screen can

be changed to the desired value.

6. Press 2nd key to remove 2nd annunciator.

7. Press RECALL key to exit reading mode.

8. Press MEMORY key to exit memory mode.

20

9-3 Automatic data storage in memory

Before auto store of data, the record interval period must be
set. When in auto store data mode, the user cannot view
other measurement parameters.

1. Setting record interval period : The record interval period

default value is “0”. Press 2nd key, then press MEMORY
key to select the desired setting time, the period time is : 0sec
(No record) à1secà3secà 10secà30secà1minà 5minà
8min à10min à15minà 30min à1hrà8hà62.5ms.
Example : Record period time setting to 1 second, display P
[00:00:01].

FAST

dB

100

90
80
70
60
50
40
30

L

31.5Hz

WA 75.2 dB

2k500125 8k L W

[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39

2. Press 2nd key, the 2ND annunciator will disappear from

the screen.

3. Use the SLM/ 1/1/ 1/3 key to desired SLM, 1/1 or 1/3 octave

band sound pressure level measurement screen.

4. Set the preset measurement time (refer to 8-3-2).

5. Press MEMORY key, enter to memory mode, the upper of

the screen shows “ M

[****] ”.

21

6. Press the START/STOP key to activate automatic data recording

to memory. The top of the screen should show “ S Auto ” and
the4 annunciator.

FAST

L

dB

100

90
80
70
60
50
40
30

31.5Hz

WA 75.2 dB

2k500125 8k L W

[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39

CAUTION : When in auto store mode, the parameter setting
cannot be changed (such as frequency weighting, time
constant, 5LEVEL6 ).

7. When the measurement time set in the preset measurement
time has elapsed or the memory is full, the meter will stop
automatically storing data. Measuring can also be halted by
pressing either the PAUSE/CONT key or the START/STOP
key.

8. The data stored can only be viewed via a PC.

22

9-4 Erase memory data

1. When the instrument memory is full, the FULL annunciator
appears in the upper right hand corner of the screen.

ID No: 00001358 Ver: 0.10

FAST

A

L

30 80

[ SLM ] 01 / 07 / 27 14:26:39

dB

130

ALL Memory are Erased !!

SOUND LEVEL METER
1/1 & 1/3 Octave Band
Real-Time Analyzer

Self-Testing......OK!!

2. Turn off the meter, press and hold down the STORE and
RECALL keys together, then turn on the meter. Continue
holding the buttons until the display reads “All Memory is
Erased !!”.

23

RS Components UK

PO Box 99, Corby
Northants, NN17 9RS
Tel: [phone]
Fax: [phone]

Sep-2002