Extech Instruments SL355 User manual

USER MANUAL
Noise Dosimeter, Datalogger, and
Sound Level Meter With PC Interface
Model SL355
Additional User Manual Translations available at www.extech.com

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1. Table of Contents
1. Table of Contents ……………………………………………………………….…….. 2
2.
Introduction …………………………………………….………………………….……
3
3.
Features …………………………………………………………………………….…..
4
4.
Meter Description ……………………………………………………………………...
4
5.
Display Description ……………………………………………………………….……
5
6.
Preparation ………………………………………………………………………….….
6
6.1 Getting Started ……….……………………………………………..……............
6
6.2 Battery Installation, Replacement, and Disposal ………………………………
6
6.3 Batter Status Symbols …………………………………………………........……
6
6.4 Microphone Installation …………………………………………..……….………
6
7.
Calibration Procedure ……………………………………………………….………...
7
8.
Dose Testing and Datalogging …………………………………………….………… 8
8.1
Overview of Dose Testing and Datalogging ……………………..………...….. 8
8.2 Running Dose Tests and Datalogger ……………………………………..……. 8
8.3 Reviewing Dose Test Setups and Measurement results ………….........…… 9
8.4 Review Stored Datalogger Data ……………………………………..........……. 9
8.5 Data Mode - Menu Table ………………………….………………………..…… 10
8.6
Data Mode - Meter Screen Shots ………………………………………..…….. 11
8.6.1
Select Dose Meter Setup from Memory ……………..………….………. 11
8.6.2 Measure and Store Dose Data ……………………...………….………… 11
8.6.3 Screen Shots for Recalling and Reviewing Dose Data …..…….………
14
9.
Sound Level Meter (SLM) Mode ……………………………………………….…….
15
9.1 SLM Menu Table ……………………...……………………………………..…....
15
9.2 SLM Screen Shots ……………………..………………………………..……..…
16
10.
Meter Setup - Software Method ……………..………………………...…….……….
18
11.
Meter Setup - Manually ………………………..………………………………………
18
11.1 SETUP Mode ……………………………….…………………...……....……….
18
11.2SETUP Mode - Menu Table …………………………..………………….……..
18
11.3 SETUP Mode - Screen Shots ……………………...……………………...……
19
11.4 OPTION Mode ……….…..……………………………………………..………..
21
11.5 OPTION Mode - Menu Table ……………………………….……...….……….
21
11.6
OPTION Mode - Basic Screen Shots …………………..………….………….. 23
11.7
OPTION Mode - Set the Time and Date ………...……..…...………….…….. 24
11.8 OPTION Mode - Editing ……………...………………………………….……… 25
12. Clear the Meter’s Memory ……………………………………………….…………… 27
13. Specifications ………………………………………………………….………………. 28
14. Maintenance …………………………………………………………………….……... 31
15.
Software Installation and Operation …………………………………….…………... 31
16. Glossary of Terms ……………………………………………………….……………. 32

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2. Introduction
Congratulations on the purchase of the Model SL355. The SL355 is a combination Noise
Dosimeter, Datalogger, and Sound Level Meter (SLM). The SL355 can be configured manually via
push-button navigation of the menu system or through the PC interface using the supplied software
(recommended for ease of use). Refer to the dedicated software User Guide on the supplied CD-
ROM for detailed instructions on using the software program for downloading data, configuring the
SL355 meter, and remotely controlling the meter.
The SL355 Noise Dosimeter is designed to test noise exposure and provide noise surveys for
compliance with OSHA, MSHA, DOD, ACGIH, and ISO standards. The SL355 monitors
accumulated noise exposure and measures frequency weighted noise exposure and peak sound
level simultaneously for % dose and TWA (time weighted average or sound exposure in dB).
Up to twenty (20) noise surveys can be recorded and up to five (5) automated dose tests can be
programmed up to 30 days in advance. Each test includes a ‘repeat’ feature where tests can be
rerun a pre-programmed number of times. Criterion Level, Threshold, Exchange rate and other
parameters are user-programmable. Noise Survey results can be viewed on the meter’s display and
downloaded using the supplied PC software.
The SL355 Sound Level Meter (SLM) displays real-time sound pressure level (SPL) readings
along with LEQ, SEL, and elapsed time as a typical type 2 SLM would. The SLM has selectable
measurement ranges: 60 to 130 & 70 to 140dB, ‘A’ and ‘C’ frequency weightings, Linear ‘Z’, and ‘C’
Peak weightings, Fast & Slow response time settings, and an adjustable energy exchange rate (Q).
The SL355 Datalogger has a built-in real-time clock for date/time stamped data records. The
datalogger can store up to 14,400 readings in the meter’s memory. Sampling time (rate) is
programmable from 1 second per reading up to 1 hour per reading. Logged readings are
downloaded using the supplied PC software.
This device has been calibrated and tested before shipment. With proper care, years of reliable
service can be expected.
Conventions of this User Guide
The SL355 is a sophisticated device with a variety of features. This User Guide is intended to
optimize the user experience with regard to ease of use and convenience.
To accomplish this, most sections of this User Guide include instructional text, a Menu table, and a
section that illustrates the actual “Screen shots” seen by the user while programming the meter.
Be sure to review all three of these approaches (instructional text, menu tables, and screen shots)
and determine if one, or a combination of the three, work best for the application at hand. If
questions arise please contact our technical support staff.

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3. Features
•Combination Dose Meter, Datalogger, and Sound Level Meter.
•User-defined measurement configurations. Selectable Criterion Level, Exchange Rate,
Threshold, Frequency Weighting, and Response Time settings.
•Completely configurable using the supplied PC software (recommended).
•Twenty (20) internal memory locations with a total capacity of 14,400 readings.
•Download Dose, TWA, and Datalogger data to a PC using supplied PC software.
•Real-time clock and date/time stamp datalogging capability.
•Keypad lock protects against inadvertent meter operation.
•Included USB PC interface and WindowsTM configuration and datalogging software.
•Kit includes a microphone, microphone clip, microphone windscreen, belt clip, batteries,
protective case, keypad cover, user guide, software CD-ROM, and USB cable.
4. Meter Description
1. Microphone input jack
2. Calibration potentiometer for 114db adjustment
3. LCD Display
4. ON-OFF and MENU button
5. Left arrow button
6. Down arrow button
7. USB PC interface jack
8. Right arrow button
9. Up arrow button
10. RUN/PAUSE and RETURN button
Keyboard cover:
Notes: Battery compartment and belt clip are located on rear of meter. Microphone lapel clip,
calibration screwdriver, microphone, windscreen, and other kit items are not pictured.

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5. Display Description
1. Over range indicator
2. Under range indicator
3. REC Flashing: Timer standby; Solid:
Recording
4. Recording Pause indicator
5. ‘Smart’ navigation buttons
6. SPL (Sound Pressure Level)
PK (Peak mode: ‘C’ frequency weighting)
PKZ (Peak mode: Linear ‘Z’ weighting)
DOSE (%dose)
LEQ (Equivalent Continuous Sound Level)
TWA (Time Weighted Average)
SEL (Single Event Noise Exposure Level)
7. SSlow (response time weighting)
FFast (response time weighting)
C‘C’ frequency weighting
A‘A’ frequency weighting
8. dB% Percent or decibel readout units
9. Battery status
10. Primary reading, date/time display, or menu items for the programming modes
11. Mode Icons:
SLM Sound level meter mode
DATA Dosimeter/Datalogger (when flashing, Data is recording and the keypad is locked;
when solid, the meter is waiting for the Timer to countdown before recording can begin)
SET UP Setup mode of operation
OPTION Option mode of operation
12. Headphone icon indicates that a SPL of over 115db has occurred
13. BEG Start test time
END Stop test time
DUR Test duration

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6. Preparation
6.1 Getting Started
1. Power the instrument by momentarily pressing the power/menu button at the upper left side of
the keypad.
2. When the unit is turned on, the model number (355) appears briefly on the left side of the LCD
and the firmware version (1.1, for example) appears on the right side.
3. The meter defaults to the SLM mode (SLM icon is shown) where the main display indicates the
sound pressure level (SPL) in db, the A/C frequency weighting setting, the F/S response time
setting, and the battery status icon (an up or down arrow will be
visible if the current reading is above or below the selected range
respectively). See screen shot diagram.
4. If the meter will not switch on, check that the batteries are installed
and are fresh.
5. To turn the meter OFF, press and hold the power/menu button for
three (3) seconds.
6. The SL355 can be used as a Sound Level Meter or a Dosimeter/Datalogger.
7. Note that the four arrow buttons are ‘smart’ navigation keys. For any given meter mode only the
active arrow buttons appear on the LCD.
6.2 Battery Installation, Replacement, and Disposal
1. Slide the rear battery cover off of the meter.
2. Remove the old batteries (if applicable) and insert three (3) ‘AAA’ 1.5V
batteries. Ensure that the battery orientation and polarity are correct. Do
not mix fresh and partially used batteries.
3. Carefully re-assemble the meter before use.
Never dispose of used batteries or rechargeable batteries in household waste.
As consumers, users are legally required to take used batteries to appropriate
collection sites, the retail store where the batteries were purchased, or wherever
batteries are sold.
Disposal: Do not dispose of this instrument in household waste. The user is
obligated to take end-of-life devices to a designated collection point for the disposal
of electrical and electronic equipment.
6.3 Battery Status
The battery status icon appears as empty when the battery is depleted. The battery symbol
indicates the remaining capacity in numbers of bars or segments, as follows:
6.4 Microphone installation
Insert the microphone plug into the connector on the top of the meter as shown in
accompanying diagram. Turn clockwise to secure in place; be careful not to over-
tighten.

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7. Calibration Procedure
1. A standard 114db acoustic calibrator is required (as shown in diagram below).
2. Insert the meter’s microphone carefully into the insertion hole of the calibrator (as shown).
3. Switch the calibrator ON and set its output amplitude to 114 db.
4. Switch the meter ON.
5. Access the Calibration mode (CL) by repeatedly pressing the MENU button until the CL XX.X
display is shown and the SLM, DATA, SETUP, and OPTION mode icons are all switched off
(refer to accompanying screen shot illustration).
6. Adjust the meter’s potentiometer (recessed at top of meter) using the supplied adjustment tool
until the display reads 114db, matching the 114db output level of the calibrator.
7. Press the RUN/PAUSE/RETURN button to save the calibration.

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8. Dose Testing and Datalogging
8.1 Overview
The dosimeter noise survey and datalogging functions operate at the same time. For example, while
the %dose and TWA (time weighted average) values are being calculated and displayed (for the
dose meter’s noise survey) individual SPL readings are being stored by the datalogger.
Noise surveys and logged data are stored in ‘RUNS’ which are memory locations (1 to 20). Note that
the meter can collect up to 14,400 readings total, spread out over the 20 RUN memory locations. The
‘RUN’ parameter is located in the DATA menu. The DATA Mode Menu table and a Screen-Shot
section are provided directly after the instructional text below:
8.2 Running the Dose Meter Noise Survey and Datalogger
1. Use the supplied software program (recommended) to configure the meter’s noise survey and
datalogging parameters (a software User Guide is provided on the supplied CD-ROM), or
manually configure the meter following the instructions provided in the SETUP and OPTION
mode sections of this guide. For compliance, the noise survey parameters must match the
requirements of the regulation/standard in question.
2. In the SETUP mode (or using the supplied software) set the Criterion Level, Exchange Rate,
Threshold, Frequency Weighting, Response time, Range, and Peak parameters. Note that if a
configuration has already been stored, it can be recalled in the SETUP mode. Reference Section
11.3 for SETUP Mode details.
3. In the OPTION mode (or using supplied software) set the Date/Time, Test Duration, Test Begin
(BEG) time, Test End time, Sample rate (logging period), Repeat, Pair, and Timer functions.
Reference Section 11.5 for OPTION Mode details.
Note: for an 8 hour Dose noise survey the minimum Sample rate is 2 seconds.
4. For the entirety of the test, the microphone should be clipped to the test person’s lapel and the
meter should be clipped to the test person’s belt.
5. To run the dosimeter/datalogger the meter must be in the DATA Mode of operation. Press the
Menu button to select the DATA Mode (if not already selected).
TIMER Notes:
•The Timer setting is critical for determining whether the test begins immediately (Timer OFF)
or at a programmed time (Timer ON).
•With the TIMER set to OFF, recording can begin immediately by pressing the RUN/PAUSE
button. When the meter is recording, the REC icon will appear solid and the DATA icon will
flash.
•With the TIMER set to ON, and with the Beginning and End times programmed, after
RUN/PAUSE is pressed recording will NOT start until the programmed Begin (BEG) time is
reached. The REC icon will be flashing (indicating that the meter is in “standby” waiting for
the Begin time); the DATA icon will be on solid.
•Up to 5 Begin/End times can be pre-set and tests can be programmed up to 30 days in
advance.

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DUR (DURATION) Notes:
•DUR allows the user to select a specific RUN Duration time.
•When a duration period is set by the user to anything other than OFF, it takes precedence
over the Timer setting so that any preset Begin and End times will be ignored. DUR is
available in the OPTION mode menu.
6. While testing, the meter’s DATA menu can be navigated (see DATA Menu table and Screen
Shots below) as long as the keypad is unlocked. This allows the user to view the current setup, %
dose, and TWA while the test is running.
7. The arrow keys are locked automatically when recording begins. Press ◄and ▼ simultaneously
to unlock the keypad. The DATA icon will cease flashing, indicating that the keypad is unlocked
and ready for navigation. To re-lock the keypad, press ▲and ► simultaneously.
8. To pause a recording, press RUN/PAUSE. The pause icon || will appear. Press again to resume.
9. To stop the recording if the END time has not been automatically set, first unlock the keypad by
pressing ◄and ▼ simultaneously and then press the MENU key. The display will show STOP
and will count down from 3 to zero; press the RUN/PAUSE button before zero is reached to
successfully stop the recording.
10. Switch the meter off to conserve battery power. To switch the meter off, press and hold the menu
button until the unit switches off.
11. %Dose and TWA calculations are viewable using the PC interface or by navigating the DATA
mode (refer to the DATA Menu table and Screen Shots below). Individually logged readings are
retrievable via the PC interface only. Follow the directions in the Software User Guide supplied on
the enclosed CD-ROM.
Testing notes:
•Do not shout into the microphone or strike the microphone as this will affect the test.
•To obtain reliable data, the user’s activities must reflect a typical workday.
8.3 Reviewing Noise Survey Setups and Measurement Results
1. Note that the PC interface can be used to review setups and measurement results. Refer to
the Software User Guide on the supplied CD-ROM for instructions. To work manually, follow
the steps below.
2. Switch the meter ON; the meter will be in the SLM mode. Press MENU to access the DATA
mode.
3. Use ►to scroll to the ‘RUN’ display. Now use▼▲ to select the desired RUN (memory
location).
4. When the desired RUN is selected, use ◄►to scroll the setup data and noise survey results
as shown in the DATA Menu table and Screen Shots below.
8.4 Reviewing Stored Datalogger Data
The stored datalogger readings can only be viewed by downloading the data to a PC using the
supplied cable and PC software program. Refer to the Software User Guide on the supplied CD-
ROM for detailed instructions.

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8.5 DATA Mode Menu Table
Display Description Display Description
HH:MM:SS
(Use ▼to scroll
items below) Current Time HH:MM:SS
(Use ►to scroll items
below) Current Time
DD:MM:YY Current Date BEG Datalogger Begin Time
SPL Sound Pressure
Level rUN†Current memory location (01-20)
DUR
Test Duration
USr (selected setup) View %DOSE and TWA
using ▲and ▼buttons
60 to 130db
70 to 140db Measurement Ranges
Er Exchange rate (Q) in db
tHr Threshold in db
CrIt Criterion level in db
LP Logging Period (mm:ss)
from 1 sec. to 1 hour
† Scroll the RUN parameter list using the ▼▲ buttons to locate the EPty XX parameter which indicates the
number of empty memory locations or runs remaining (00 to 20); if recording is attempted with all memory
locations full, the meter will display ‘EPty00’ indicating that there are no (zero) empty storage locations
remaining (data must then be cleared from the meter before continuing; use the OPTION menu to clear
data).