Extech 407355 Operating Manual

User's Guide

Noise Dosimeter with PC Interface

Model 407355

Introduction

Congratulations on your purchase of the Extech 407355 Personal Noise Dosimeter. The 407355 is designed to test noise exposure in accordance with OSHA, MSHA, DOD, ACGIH, and ISO standards. Fast and easy on-site surveys help determine noise reduction requirements. The meter can also be used in SLM (sound level meter) mode where sound pressure levels are monitored from 70 to 140dB. The SLM (sound level meter) mode has a datalogging feature that can record up to 8800 readings which can be downloaded to a PC for analysis. Note: In DOSIMETER mode, the individual measurements are NOT datalogged and cannot be recalled.

The built-in RS-232 PC interface offers the following capabilities:

 In SOUND LEVEL METER (SLM) MODE: The meter can be connected to PC while

taking measurements so that readings can be stored in a file and readings can be viewed in a variety of display configurations (graph, list, etc.).

 In DOSIMETER mode: The meter can perform a noise survey after which the user

can transfer the survey data to a PC.

Careful use of this device will provide years of reliable service.

Warranty

EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects

in parts and workmanship for one year from date of shipment (a six month limited warranty applies to sensors and cables). If it should become necessary to return the instrument for service during or beyond the warranty period, contact the Customer Service Department at (781) 890-7440 ext. 210 for authorization or visit our website www.extech.com for contact information. A Return Authorization (RA) number must be issued before any product is returned to Extech. The sender is responsible for shipping charges, freight, insurance and proper packaging to prevent damage in transit. This warranty does not apply to defects resulting from action of the user such as misuse, improper wiring, operation outside of specification, improper maintenance or repair, or unauthorized modification. Extech specifically disclaims any implied warranties or merchantability or fitness for a specific purpose and will not be liable for any direct, indirect, incidental or consequential damages. Extech's total liability is limited to repair or replacement of the product. The warranty set forth above is inclusive and no other warranty, whether written or oral, is expressed or implied.

CE Certification

The CE-mark indicates compliance to the EMC directive

Safety EN 61010-1 (1993) and IEC 1010-1 (1990); Safety requirements for

EMC Emission EN 50081-1 (1992): Generic emission standard

Part 1: Residential, commercial, and light industry EN 50081-2 (1993): Generic emission standard Part 2: Industrial environment

EMC Immunity EN 50082-1 (1992): Generic immunity standard Part 1: Residential, commercial, and light industry

electrical equipment for measurement, control, and laboratory use

CISPR22 (1993): Radio disturbance characteristics of information technology equipment. Class B limits.

FCC rules, part 15: Complies with the limits for a Class B digital device

RF immunity implies that sound level indications of 70dB or greater will be affected by no more than ±1.5dB

EN 50082-2 (1995): Generic immunity standard Part 2: Industrial environment RF immunity implies that sound level indications of 70dB or greater will

be affected by no more than ±1.5dB

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Specifications

Display Multi-function LCD Units of measure dBA (‘A’ weighted decibels) for sound level

% DOSE for accumulated noise exposure

Measurement ranges 70 to 140dBA for sound level (SPL) measurements

0.01 to 9999 %DOSE for noise exposure surveys Standards applied ANSI S1.25-1991 A-weighting; ISO-1999; BS 6402: 1983 Criterion level 80, 84, 85, and 90dB (selectable) Threshold level 70 to 90dB in 1dB steps (selectable) Exchange rate 3, 4, 5, and 6dB (selectable) High level detector appears on LCD when measurement exceeds 115dBA Peak flag PK appears on LCD when measurement exceeds 140dBA Accuracy ±1.5dB Frequency weighting ‘A’ weighting Frequency response 31.5Hz to 8 kHz Response time F (FAST) and S (SLOW) selectable Datalogging capacity 8800 sets Operating Temperature 32 to 122

F (0 to 50oC) Operating Humidity 10 to 90% RH Storage Temperature 14 to 140

F (-10 to 60oC) Storage Humidity 10 to 75% RH Battery power Four (4) 1.5V ‘AAA’ batteries Battery life 40 hours (approx.) Dimensions 4.2 (L) x 2.4 (W) x 1.3 (H)"

106 (L) x 60 (W) x 34 (H) mm

Weight Approx. 12.3 oz. (350g) with batteries

Descriptions

Display Description

1. FAST Response Time mode

2. SLOW Response Time mode

3. Noise Exposure test active

4. Memory mode alert

5. Noise Exposure test paused

6. Unit of measure for Noise Exposure test

7. Battery Status Indicator

8. Event memory banks (E1-E5)

9. 115dB limit (headphone) indicator

10. Numerical display digits

11. Unit of measure for sound level readings

12. 140dB PEAK indicator

13. Elapsed time mode for noise exposure tests

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Meter Description

1. Microphone (lapel clip not shown)

2. Microphone cable

3. Microphone connector

4. LCD display

5. Push-buttons: ON-OFF Press to turn the meter ON; Press and hold

to turn the meter OFF.

RESET This button has a variety of uses including

clearing stored data and accessing the Programming mode as described in the manual.

RUN Press to begin a noise survey test in Dosimeter

mode or datalogging in SLM mode. Also used as the Left Arrow in the Programming mode

CLOCK Press to view the Date and Time. Also used

as the Right Arrow in Programming mode

MODE Press to select ELAPSED TIMER, SLM (dBA)

mode, or noise survey (%DOSE) mode. Also used as the Down Arrow in the Programming mode

EVENT Press to select a memory bank (E1 through

E5). Also used as the Up Arrow in the Programming mode

6. RS-232 PC Interface plug

7. RS-232 PC Interface jack

8. Calibration potentiometer

9. Battery compartment screw

10. Belt clip / Battery compartment cover

11. Battery compartment

12. Microphone jack

13. Housing screws (service personnel only)

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Operation

Getting Started

1. Power the instrument by pressing the green button.

2. When the unit is turned on, all display annunciators switch on briefly followed by ‘dOSE’, the Criterion Level (Lc), Threshold Level (Lt), and Exchange Rate (ER) respectively. These parameters are defined in the Noise Exposure related sections of this manual.

3. If the meter does not switch on when the power button is pressed, check that the batteries are installed and are fresh. Refer to the Battery Replacement section of this manual.

4. To turn the meter OFF, press and hold the green power button; the display will count down from 3dB to 0dB and then switch off.

5. The 407355 can be used as a Sound Level Meter or a Dosimeter.

Sound Level Meter Operation (dBA)

Press the MODE button repeatedly until the unit of measure is dBA (A-weighted decibels). In SLM mode the meter operates as a Type 2 sound level meter. The 407355 measures and displays sound pressure levels from 70 to 140dB. Read the measured sound level on the LCD. For Sound Level measurements < 68dBA the LCD will display dashed lines. For readings > 115dBA, the headphone icon appears. For readings > 140dBA, the Peak Detector PK icon appears.

Datalogging

In Sound Level Meter (dBA) mode, the internal memory of the meter can store up to 8800 readings. Press the RUN key to start recording the measured readings. The MEM icon will appear in the display. To stop datalogging, press the RUN key again. The MEM icon will no longer be displayed on the screen. To download the data to a PC, refer to the PC Interface section in this manual.

Note: If the low battery mark is flashing or Dosimeter surveys E1 through E5 have been saved in memory, the datalogging function will not operate. The memory must be cleared. To clear memory, turn the meter off then hold down the RUN key and turn the meter on. E-

EP will appear in the display to indicate that all memory data has been cleared.

Dosimeter Operation (Accumulated Noise Exposure - %DOSE)

1. Program the Response Time (Fast or Slow), Criterion Level (Lc), Exchange Rate (ER), and Threshold Level (Lt) manually (see Programming section) or through the supplied software (see PC Interface section).

2. Use the MODE button to select %DOSE as the unit of measure.

3. Select an unused Event Bank (E1 through E5) using the EVENT button.

4. Attach the meter to the user’s belt buckle, breast pocket, or where convenient

5. Clip the microphone as close as possible to the user’s ear (shirt collar, for example) using the lapel clip.

6. Route the cable as to not hinder the working movements of the user.

7. Press the RUN button to begin measuring accumulated noise exposure. The Clock display icon will switch on.

8. Press the RUN button momentarily to PAUSE the test (PAUSE display icon will switch on). Press the RUN button again to resume the test (PAUSE icon will switch off).

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9. Use the MODE button at any time to view the elapsed time of the test. Press the MODE button until the TIME display icon appears. Now the elapsed time will appear in hours and minutes. Press the RUN button again to return to the %DOSE display.

10. To end the noise survey, press and hold the RUN key for 3 seconds. Read the accumulated noise exposure value on the LCD.

11. Testing notes:

 Never shout into the microphone as this will affect the test.  To obtain reliable data, the user’s activities must reflect a typical working day.  For best results, test over the course of several days and average the %DOSE

Refer to the dosimetry parameter descriptions below: Event Select

Press the EVENT button to enter the EVENT mode. Each time the EVENT button is pressed the LCD increments the Event bank (E1 through E5). Each bank is a memory location. The user can store (or write over) the data in any of these locations. Each bank location (E1, for example) is displayed on the LCD along with the stored data. If data is present in a bank, the bank ID blinks. To erase data in a bank, press and hold the RESET button until the display ID stops blinking.

% DOSE

The unit of measure, % DOSE, is used to quantify noise exposure measured during a work shift. 100% dose is the maximum allowable noise exposure in accordance with OSHA, MSHA, DOD, ACGIH, and ISO standards. Most standards specify Criterion Level, Exchange Rate, Response Time, and Frequency weighting for the dosimeter as discussed next.

CRITERION LEVEL (Lc)

To take an on-site noise exposure survey in accordance with standards such as OSHA and MSHA, the dosimeter’s Criterion Level must first be set. The 100% DOSE parameter discussed above is determined by the following equation: 100% DOSE = Criterion Level for 8 hours. Each country has a unique Criterion Level (most countries, including the U.S., use 90dB). The Criterion level is selectable (80, 84, 85, or 90dB). Select the appropriate level per the Programming section of this manual.

EXCHANGE RATE (ER)

Exchange rate is best illustrated by example; refer to the following example: Since 100% DOSE = Criterion Level for 8 hours, a person would receive 50% DOSE in 4 hours if the noise level equals the Criterion Level setting. Now consider a Criterion Level of 90dB, a noise measurement of 95dB (5dBA higher than the Criterion Level), and an Exchange Rate of 5dB; in this example a 100% DOSE would be received in only 4 hours. This is because with a 5dB Exchange Rate, a 5dB increase in sound level is considered a doubling of the DOSE. Other Exchange Rates can be selected (3, 4, 5, or 6dB). Refer to the local regulations or standards.

FAST (F) SLOW (S) RESPONSE TIME

Set the response time to Fast (F) to capture quick bursts of sound such as discharging firearms, fireworks, hammering, and other impulse noises. Use the Slow (S) setting if the noise under test is more of a continuous drone or background din. The Slow setting is typically specified by OSHA and MSHA standards for use in noise surveys. Refer to the Programming section of this manual to set the response time.

THRESHOLD LEVEL (Lt)

The threshold level is the sound level at which the 407354 begins to integrate noise into the exposure test. For example, if the threshold level (Lt) is set to 85dB, the meter will integrate all noise that equals or exceeds 85 dB. Sound levels below this threshold would not be included in the dose calculation. See the Programming section to change the level. The Threshold Level can be set from 70 to 90dB in 1 dB steps.

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