Isotech SLA-1358 User manual

ISO-TECH
Sound Analyser
Real Time 1/1 & 1/3 Octave band Analysis
SLA-1358
INSTRUCTION MANUAL
L

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
(LA, LC, LP)...........................................................14
8-3 Leq and LEmeasurement ....................................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

1
I. SAFETY INFORMATION
qRead the following safety information carefully before
attempting to operate or service the meter.
qUse the meter only as specified in this manual, otherwise the
protection provided by the meter and general operation may
be impaired.
qEnvironmental conditions
Altitude up to 2000 metres
Relative humidity 90% max.
Ambient operating temperature 0 〜40℃
qMaintenance & 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.
qSafety symbols
Complies with the EMC directive.

2
II. GENERAL INFORMATION & FEATURES
The SLA 1358 meter allows digital 1/1-octave and 1/3-octave
analysis in real time.
qFive 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)
qRS-232 interface for PC connection
qData Logger function
qReal time clock with calendar
qBoth AC and DC signal output is available for level or graphic
recorder
qAuto-Ranging for SPL function
III.SPECIFICATIONS
qStandard applied : IEC 60651 type2, 60804 type 2, ANSI S1.4
type2, IEC 1260 (1995).
qDisplay : 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.

3
qAccuracy : ±1.5dB (ref 94dB @1kHz)
qMeasurement Frequency range : 25Hz – 10KHz
qDynamic range : 100dB (Sound level meter mode)
70dB (Frequency analysis mode)
qMeasurement range : 30dB – 130dB
qSound 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
qFrequency weighting : A, C, P (Flat)
qTime weighting : Fast, Slow
qMicrophone : 1/2 inch electret condenser microphone.
qDisplay warning indicator :
OVER indicator (Input signal over the upper limit)
UNDER indicator (Input signal under the lower limit)
qWarm-up time : Less than 20min
qMemory 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

4
qAC output : 2 Vrms at FS (full scale).
output impedance approx. 600Ω.
qDC output : 10mV/dB.
output impedance approx. 100Ω.
qPower : Qty 4, C size 1.5V (LR14) alkaline batteries.
External DC power supply : 6 Vdc, 1A.
qBattery life : Approx. 2 hours continuous use
qOperating Temperature/Humidity : 0℃to +40℃,10 to 90%RH.
qStorage Temperature/Humidity : -10℃to +60℃,10 to 75%RH.
(battery removal)
qDimensions & Weight : 34.5(H) × 10(W) × 6(D) cm
Approx. 950g (including batteries).
qAccessories : 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, 3.5fplug, AC
adapter.

5
IV. CONTROLS AND FUNCTIONS
4-1 Parts description
FAST L
2k
[ 1 / 3 OCT ] 01 / 06 / 19 14:26:39
20
40
31.5Hz 500125
60
80
dB
100 A W
W8k L
65.2 dB
IEC 1260 CLASS2
OFFON
POWERCAL
IEC LR 14 1.5V X 4
ACCU RACY : ¡ Ó1.5dB
OFFON
DCAC
CONTRAST
OUTPUT
DC6VLIGHT
SOUND ANALYZER
IEC 651 IEC 804 TYPE 2
1/1 & 1/3 OCTAVE BAND
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

6
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.

7
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 (L
E
), 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”.

8
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
à30sà1mà5mà8mà10mà15mà30mà1hà62.5ms
h.) ENTER key
Store the new date and time and start the time clock.
i.) 3Cursor4key
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

9
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”.

10
4-3 Measurement screen
1. Sound pressure level measurement screen
[ SLM ] 01 / 07 / 27 14:26:39
A
L
30 80
FAST
dB
130
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 3Cursor4key to move the cursor to the desired
point. The frequency and level are then shown on the upper
part of the screen.
68.4 dB
[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39
50
31.5 125Hz
30 8k2k500
AL
100
dB
70
90
FAST 2k Hz
L W
40
60
80

11
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 3Cursor4key
to move the cursor to the desired point. The frequency and
level are then shown at the top of the screen.
[ 1 / 3 OCT ] 01 / 07/ 27 14:26:39
31.5Hz30
50
70
2k500125 8k L W
A
FAST
90
dB LW 75.2 dB
100
60
80
40
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.
[ SLM ] 01 / 06 /1 9 14:2 6:39
FAST
30
A
L
80
dB
130

12
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 5LEVEL6key to set the required numbers.
3. Press 3Cursor4key to move between different fields &
locations (year/month/day/hour/minute/second)
4. Press 5LEVEL6key to set the number.
5. When the setting is correct, press the ENTER key to exit
this mode.

13
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 log10
0P
P
Where P = rms measured sound pressure level
P0= rms reference sound pressure level (deemed to
be 20mPa)
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.
LEmeasurements are almost identical to Leq measurements

14
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 LEmeasurement
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... [ SLM ] 01 / 07 / 27 14:26:39
A
L
30 80
FAST
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.

15
70
500
[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39
125Hz 31.5
30
50
8k L W2k
A
FAST L
90
dB 75.2 dBW
40
60
100
80
[ 1 / 3 OCT ] 01 / 07/ 27 14:26:39
31.5Hz30
50
70
2k500125 8k L W
A
FAST
90
dB LW 75.2 dB
100
60
80
40
3. Use the FREQ WGHT key to select the desired LA, LCor LP
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 5LEVEL6key 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 5LEVEL6key is not activated.
[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39
500
70
125Hz 31.5
60
40
30
50
A
FAST L
100
80
90
dB
WL8k2k
75.2 dBW

16
8-3 Leq and LEmeasurement
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.
L
[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39
FAST A W 75.2 dB
100
Hz 31.5 125 500 2k WL8k
dB
90
70
50
30
60
40
80

17
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 LP
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 5LEVEL6key 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
5LEVEL6key 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 LAeq , LAE or other
parameter value.
Note : In this measurement mode, the frequency weighting,
time weighting and SLM/ 1/1/ 1/3 modes cannot be
changed.

18
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.
70
[ 1 / 1 OCT ] 01 / 07 / 27 14:26:39
31.5Hz
50
30
40
60
2k500125 8k L W
L
FAST
dB
90
80
100
WA 75.2 dB
4. Press the STORE key, one set of data is stored in the [0001]
memory address. The address counter is increased by one .