Extech Instruments SL250W User manual

User Manual

SL250W Sound Meter

Bluetooth® Connectivity with the ExView® Mobile App

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Table of contents

1 Introduction..... ................. ..... ..... ..... ...................... ..... ..... ... 1

2 Safety ... ..... ..... ................. ..... ..... ..... ................. ..... ..... ..... ... 2

3 FCC Compliance ...... ..... ................. ..... ..... ..... ..... ................. 3

4 Product Description . ..... ..... ............ ..... ..... ..... ..... ................. 4

4.1 Meter Description .................. ..... ..... ........................... 4

4.2 Function Buttons ......... ..... ........................... ..... .......... 4

4.3 Display Symbols.... ..... ..... ........................... ..... ..... ...... 5

5 Operation ... ..... ................. ..... ..... ..... ................. ..... ..... ..... ... 6

5.1 Powering the Meter .. ..... ..... ..... ..... ............ ..... ..... ..... .... 6

5.2 Auto Power Off (APO)................ ..... ..... ........................6

5.3 Taking Measurements ..... ..... ................. ..... ..... ..... .......6

5.4 Fast/Slow Response .... ..... ..... ..... ................. ..... ..... ..... 7

5.5 Data Hold Function ..... ..... ...................... ..... ..... ..... ...... 7

5.6 LCD Backlight .......... ..... ..... ..... ................. ..... ..... ..... ... 7

5.7 MAX/MIN Readings ............ ..... ..... ..... ................. ..... ... 7

5.8 Bluetooth Operation .. ................................ .................. 7

6 Maintenance.. ..... ..... ..... ..... ............ ..... ..... ..... ..... ................. 8

6.1 General Cleaning ............... ..... ........................... ..... ... 8

6.2 Battery Replacement.... ..... ................. ..... ..... ..... .......... 8

7 Specifications.......................... ..... ........................... ..... ......9

7.1 General Specifications ............. ..... ..... ..... ................. .... 9

7.2 Measurement Specifications .... ..... ..... ..... ..... ................. 9

7.3 Environmental Specifications .. ..... ..... ................. ..... ..... . 9

7.4 Connectivity Specifications .... ................. ..... ..... ..... ..... 10

8 Two-year Warranty........................... ..... ........................... .. 11

8.1 Calibration and Repair Services.......................... ..... .... 11

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Introduction

Thank you for selecting the Extech SL250W Sound Meter. This meter meas­ures sound level with its built-in microphone, situated at the top of the meter.
Sound level measurements are shown on the backlit LCD in decibel (dBa)
units.

The meter includes Bluetooth connectivity, MAX/MIN memory, selectable
Fast/Slow response, auto power off, data hold, backlit LCD, and tripod mount.

Using the Extech ExView mobile app, you can pair your smart devices with
the meter using Bluetooth. The app and the W Series meters were developed
together for seamless integration. Download the free app from the App Store
(iOS®) or from Google Play (Android™).

This quality instrument is designed to provide years of reliable service, high
accuracy and simple operation. Please visit the Extech website for additional
information and world-class support.

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CAUTION

• Check for damage to the device’s housing, sensor, display, and battery compartment
before use. If obvious damage or abnormalities are noticed, please discontinue use
and return the device for service.

• Do not attempt to open the meter housing or access the sensor module. There are no
user-serviceable components in this device.

• Replace the batteries immediately after the low battery symbol appears. If the device is
to be stored for a period of months, please remove the batteries and store separately.

• Do not store the device in high temperature or humidity environments, in flammable or
combustible areas, or where a strong electromagnetic field is present.

• This device is designed and produced following the strict requirements of SJ/T 10423
General Specification for Sound Level Meters.

• This device is CE certified.

Safety

Please read all safety information before using this device

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WARNING

Changes or modifications not expressly approved by the party responsible for compliance
could void the user's authority to operate the equipment.

FCC Compliance

This equipment has been tested and found to comply with the limits for a
Class B digital device, pursuant to part 15 of the FCC Rules. These limits are
designed to provide reasonable protection against harmful interference in a
residential installation. This equipment generates, uses, and can radiate radio
frequency energy and, if not installed and used in accordance with the instruc­tions, may cause harmful interference to radio communications. However,
there is no guarantee that interference will not occur in a particular installation.
If this equipment does cause harmful interference to radio or television recep­tion, which can be determined by turning the equipment off and on, the user is
encouraged to try to correct the interference by one or more of the following
measures:

1. Reorient or relocate the receiving antenna.

2. Increase the separation between the equipment and receiver.

3. Connect the equipment into an outlet on a circuit different from that to
which the receiver is connected.

4. Consult the dealer or an experienced radio/TV technician for help.

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1. Microphone with wind screen attached

2. Backlit LCD (detailed below)

3. Function buttons (detailed below)

4. Tripod mount

5. Battery compartment

4.2 Function Buttons

Power / Bluetooth button

Long press to switch the device on. Short press to switch off.

With the meter powered, long press to switch Bluetooth on/off.

Short press to switch the meter off directly from the Bluetooth mode.

MAX/MIN button

Short press to cycle through MAX/MIN readings. The memories are
cleared each time meter power is cycled.

Data Hold / Backlight button

Short press to freeze/unfreeze the displayed reading. HOLD will display
when data hold is active.

Long press to switch the LCD backlight on/off.

Product Description

4.1 Meter Description

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FAST / SLOW button

Short press to toggle the Fast and Slow modes. In Fast mode (125 ms)
sounds that peak very quickly, such as a firework ignition or a rifle dis­charge, can be captured. Slow mode (1 second) is intended for sounds
that are continuous, such as the drone of machinery.

APO ON/OFF With the meter on, long press the power and H buttons to switch APO

on/off. The APO symbol

is displayed when APO is enabled. APO is

reset each time the meter power is cycled.

1. Bluetooth active

2. A-weighted (dBa) sound level reading

3. Maximum reading

4. Minimum reading

5. Data Hold mode

6. Battery status icon

7. Slow response mode

8. Fast response mode

9. Auto Power Off (APO) symbol

Product Description

4.3 Display Symbols

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to switch the meter on. Short press the power
button to switch the meter off. If the meter does not switch on, check the bat­teries for proper orientation.

When the battery icon appears on the display, replace the batteries immedi­ately to ensure accurate readings.

5.2 Auto Power Off (APO)

The meter switches OFF automatically five (5) minutes after the last button
press.

The default mode for APO is ON (the APO symbol

on the display indicates

that APO is enabled).

To switch the APO function off, with the meter switched on, long press the
power

and H buttons. The APO symbol will switch off, indicating that the

function is disabled. APO is reset each time the meter’s power is cycled.

Repeat this process to switch APO back on manually.

5.3 Taking Measurements

1. Long press the power button

to switch the meter on.

2. Hold the meter in hand, set it on a desk or table, or mount it on a tripod in

the area under test.

3. Read the sound level measurement on the LCD. Sound level measure-

ments are presented in A-weighted decibel units. A-weighted measure­ments simulate the response curve of the human ear to sound.

4. If the measurement is over range, OL will appear on the display in place of

a typical reading. If the measurement is under range, UN will appear.

CAUTION

Do not touch or otherwise obstruct the microphone.

Do not allow liquids to come in contact with the microphone.

Do not allow dust or other particles to enter the microphone.

Use the windscreen to cover the microphone in windy environments.

Operation

5.1 Powering the Meter

The meter operates on three (3) 1.5 V (AAA) batteries, installed in the rear
compartment.

Long press the power button

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to switch the display backlight on or off.

Excessive use of the backlight will shorten battery life.

5.7 MAX/MIN Readings

When the device is switched on, it begins tracking the highest (MAX) and low­est (MIN) readings.

Short press the MAX/MIN button to step through the MAX/MIN memories.
The memories are cleared each time the meter power is cycled.

Press the MAX/MIN button again to exit this mode (MAX and MIN symbols
switch off when you exit).

5.8 Bluetooth Operation

Long press the Bluetooth button

with the meter on, to switch Bluetooth on

or off. This communication symbol

is shown when Bluetooth is on.

The Bluetooth utility allows you to remotely monitor readings on an iOS or An­droid smart device using the Extech ExView mobile app designed for use with
this meter.

Download the ExView mobile app from the App Store for iOS devices or from
Google Play for Android devices. Instructions for mobile app use are available
from the ExView product page on the Extech website (link below).

Switch APO off when using Bluetooth by pressing and holding the power

and H buttons for 2 seconds (the APO symbol will switch off). This will pre­vent the meter from automatically switching off while you are logging data or
monitoring readings in real time on your smart device.

Operation

5.4 Fast/Slow Response

Short press the Fast/Slow button to toggle the meter’s response time. Use the
Fast response mode (125 ms) to capture sounds that peak very quickly such
as fireworks. Use the Slow response mode (1 second) to monitor consistent
sounds such as the hum, or drone, of machinery.

5.5 Data Hold Function

Short press the Data Hold (
ings. While Data Hold is active, HOLD will appear on the LCD.

5.6 LCD Backlight

Long press the backlight button

H) button to freeze/unfreeze the displayed read-

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CAUTION

Warning: Do not open the housing or microphone module. Service should only be per­formed by factory personnel, there are no user-serviceable components in this device.

appears, replace the batteries immediately, as explained below.

1. Switch the meter off and remove the rear battery compartment cover.

2. Replace the batteries, observing correct polarity. Always use batteries of

the same type.

3. Secure the battery compartment before use.

Do not dispose of used batteries or rechargeable batteries in house-

hold waste.

Maintenance

6.1 General Cleaning

Wipe the housing with a damp cloth as necessary to clean. Do not use abra­sives or solvents to clean this device. Do not allow moisture to enter the mi­crophone or the meter housing.

6.2 Battery Replacement

This device is powered by three (3) 1.5 V (AAA) batteries. When the low bat­tery symbol

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appears when batteries are low

Reading update rate

Fast mode: One reading every 125 ms

Slow mode: One reading per second

Microphone type

Condenser 1.3 cm (0.5 in.)

Meter power Three (3) 1.5 V (AAA) batteries

Dimensions 6.1 x 2.2 x 1.1 in. (154 x 55 x 28 mm)

Weight 4.1 oz. (116 g)

Specifications

7.1 General Specifications

Display 4 digit (9999) backlit multifunction LCD

Over range indication OL is displayed when measurements are above the specified

Low battery indication Battery symbol

7.2 Measurement Specifications

Accuracy specifications apply for the following conditions:

Temperature: 73.4℉ ± 9℉ (23℃ ± 5℃); Relative Humidity: < 90 %

Temperature coefficient: 0.1 x accuracy /℃

Measurement range 30 to 130 dB (A weighted)

Display resolution 0.1 dB

Measurement accuracy ± 1.5 dB

Frequency Response 31.5 Hz to 8 kHz

measurement range. UN is displayed when sounds are below
the specified range.

7.3 Environmental Specifications

For indoor use only

Altitude 6562 ft. (2000 m) maximum

Pollution degree 2

Operating conditions 32 to 104℉ (0 to 40℃); < 80% RH

Storage conditions –4 to 140℉ (-20 to 60℃); < 80% RH

Drop-proof rating 3.3 ft. (1 m)

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Specifications

7.4 Connectivity Specifications

Connectivity Bluetooth (with ExView app)

ExView app compatibility iOS 13.0 and Android 9.0 or higher

Transmission distance Up to 295.3 ft. (90 m) with no line-of-sight obstruction

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Two-year Warranty

FLIR Systems, Inc. warrants this Extech brand instrument to be free of
defects in parts and workmanship for two years from date of shipment (a six­month limited warranty applies to sensors and cables). To view the full war­ranty text please visit:

8.1 Calibration and Repair Services

FLIR Systems, Inc. offers calibration and repair services for the Extech

brand products we sell. We offer NIST traceable calibration for most of our
products. Contact us for information on calibration and repair availability, refer
to the contact information below. Annual calibrations should be performed to
verify meter performance and accuracy. Product specifications are subject to
change without notice. Please visit our website for the most up-to-date prod­uct information:

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