Extech 403407 Instruction Manual

Model 403407

Sound Level ProbeMeter™

 A and C Weighting

 Fast and Slow Response

 Max Hold

 Type II Compliance

1. INTRODUCTION

Congratulations on your purchase of Extech’s Sound Level ProbeMeter™. This professional
meter, with proper care, will provide years of safe reliable service.

INSTRUCTION MANUAL

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2. SPECIFICATIONS

General

Display 31/2 digit LCD, 1999 count
Low battery The battery symbol appears in the LCD.
Display rate Once per second
Operating
En vironment
Storage
Environment
Batteries Four 1.5V AAA size
Battery life 50 hours typical
Dimensions 107 x 8.5 x 1.6” (217mm x 44mm x 40mm)
Weight 6.4oz. (168g) including batteries

Electrical

Applicable standards ANSI S1.4-1983 Type 2

Measurement range Lo range 35-90dB

Resolution 0.1dB
Frequency
Weighting
Frequency Range 31.5Hz to 8000Hz
Detector True RMS
Dynamic range 55dB
Max Hold decay time <1dB/3 minutes with reset
Time weighting S(slow) and F(fast) selectable
Microphone ½” electret condenser
DC Output
AC Output 0.55V rms at full scale of selected range, output

Warm-up <5seconds
Calibration conditions 1000Hz, 94dB, 20oC, 65%RH, 75-130dB range
Temperature effect <0.5dB (-10oC to 50oC)
Humidity effect <0.5dB for 30% to 90%RH at 40oC, 1kHz

3. CONTROLS

1. Microphone

2. LCD display

3. Normal / Max mode switch

4. A/C weighting switch

5. Fast / Slow response switch

6. Power / Range switch

7. Calibration adjustment

8. Battery compartment (rear)

9. AC / DC output jack

14oF to 122oF (-10oC to 50oC), <90% RH

-4oF to 140oF (-20oC to 60oC), <80% RH, batteries
removed

IEC 651-1979 Type 2
JIS C 1502

Hi range 75-130dB

A and C selectable

10mV/dB, output impedance 100Ω
impedance 600Ω

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4. OPERATION

4.1 Power and Range.

Slide the Power switch to the Lo (35 to 90dB) position or the Hi (75 to 130dB) position.
Select “Lo” or “Hi” to match the range of the sound level to be measured. If “OVER” or
“UNDER” appears in the LCD, switch to a higher or lower range as required.

4.2 A or C weighting

Slide the Weighting switch to the A or C position. The LCD will reflect which weighting
mode is currently selected. Use ‘A’ weighting to have the meter respond as the human
ear would with regard to frequency response (the human ear boosts and cuts amplitude
over the frequency spectrum therefore it is not ‘flat’ responding). ‘A’ weighting is used for
environmental measurements, OSHA regulatory testing, law enforcement, and
workplace design. Select ‘C’ weighting for a flatter response measurement (especially
for lower frequencies). ‘C’ weighting is suitable for the sound level analysis of machines,
engines, etc.

4.3 Fast or Slow response

Slide the Response switch to the Fast or Slow position. The LCD will reflect the currently
selected mode. Selection of Fast or Slow is determined by the application and any
directives or standards related to that application. For example, most hearing
conservation or OSHA related testing is done using SLOW and A weighting.

4.4 Max Hold

Slide the Max / Normal switch to the MAX position to display the maximum reading
during the measurement period. In the Max position, the LCD will hold the highest
reading measured and will update only if a higher reading is measured. Slide the switch
to the Normal position for continuous sound level readings.

4.5 AC and DC Output

The mini-phone jack located on the bottom of
the meter provides outputs that can be used to
record the measured sound levels on a tape
recorder, strip chart recorder or other recording
device.

4.6 Tripod Mount

For long-term measurements, the meter may be mounted on a tripod. The supplied
tripod adaptor can be installed on the rear of the meter.

1. Remove the rear battery compartment cover screw.

2. Install the tripod adaptor in place of the screw.

5. CALIBRATION

Meter calibration using an acoustic calibrator should be performed regularly.

1. Place the calibrator over the microphone.

2. Set the meter to; Hi range, A weighting and Slow response.

3. Set the calibrator to 1kHz and 94dB.

4. Adjust the calibration adjustment for a reading of 94.0dB.

6. WINDSCREEN

The meter is supplied with a windscreen. The primary purpose of
this is to reduce noise generated across the face of the
microphone do to wind. The windscreen also protects the
microphone from damage from dust and dirt. It is suggested that
the windscreen be used for all measurements.

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7. BATTERY REPLACEMENT

1. The “battery” symbol will appear in the LCD when the batteries need replacement.

2. Remove the screw securing the rear battery compartment cover.

3. Replace the four AAA batteries and reinstall the cover.

8. CALIBRATION / REPAIR SERVICES

Extech offers complete repair and calibration services for all of the products we sell. For
periodic calibration, NIST certification or repair of any Extech product, call customer
service for details on services available. Extech recommends that calibration be performed
on an annual basis to insure calibration integrity.

9. 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 on 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 [phone] for authorization. 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.

10. TYPICAL A WEIGHT SOUND LEVELS

dB

140

50HP Siren (100')

Jet takeoff (200')

Riveting machine

Subway (20')

Pneumatic drill (50')

Vacuum cleaner (10')

Large store

Small office

Night residential area

Whisper (5'0)

Threshold of hearing

130
120

110

100

Chain saw

90

80

Freight train (100')

70
60

50

40
30

20

10

0

Boiler room

Speech (1')

Large Office

Residence

Sound studio

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