REED ST-805 User manual

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Model ST-805
Sound Level Meter
Instruction
Manual

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Contents
General Description....................................................................... 2
Safety Information ......................................................................... 3
Specications................................................................................ 4
Instrument Description ...............................................................5-7
Operating Precautions.................................................................. 7
Measurement Procedures .................…....................................... 8
Calibration Procedures.................................................................. 8
Battery Replacement..................................................................... 9
General Description
To ensure that you can get the most from it, we recommend that you r
ead and follow the manual carefully before use.
This unit conforms to the IEC651 type 2, ANSI S1.4 type 2 for Sound
Level Meters.
This Sound Level Meter has been designed to meet the measurement
requirements of safety engineers, health, industrial safety ofces and
sound quality control in various environments.
• Ranges from 30 to 130dB at frequencies between 31.5 Hz and 8 kHz.
• Display with 0.1dB steps on a 4-digit LCD.
• Two equivalent weighted sound pressure levels, A and C.

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Safety Information
Read the following safety information carefully before attempting to
operate or service this meter. Use this meter only as specied in this
manual; otherwise, its proper operation may be impaired.
Environmental Conditions
1. Altitude up to 2000 meters
2. Relatively humidity up to 90% R.H. max.
3. Ambient temperature: 0~40°C
Maintenance & Cleaning
1. Repairs or servicing not covered in this manual should only be
performed by qualied personnel.
2. Periodically wipe the case with a dry cloth. Do not use abrasives or
solvents on this instrument.
Safety Symbols
Meter is protected throughout by double insulation or reinforced
insulation.
When servicing, use only specied replacement parts.
Comply with EMC
For service on this or any other REED product or information on other
REED products, contact REED Instruments at [e-mail].

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Specifications
Standard Applied: IEC651 type 2, ANSI S1.4 type 2
Frequency Range: 31.5Hz~8KHz
Measuring Level Range: 30~130 dB
Resolution: 0.1 dB
Accuracy: ±1.5 dB (under reference conditions)
Frequency Weighting: A & C
Time Weighting: Fast: 125mS: Slow: 1 sec.
Level Ranges: Lo: 30~100 dB; Hi: 60~130 dB
Display: 4-digit LCD
Display Update: 0.5 sec.
Alarm Function: “OVER” is show when input is out of range
Maximum Hold: Hold readings the Maximum Value, with decay
< 1dB/3minutes
Microphone: 1/2 inch electret condenser microphone
Calibration: Electrical calibration with the internal
oscillator (1kHz sine wave)
Auto Power Off: Meter automatically shuts down after approx.
15 minutes of inactivity
Power Supply: One 9V battery, 006P or IEC 6F22 or NEDA
1604 (included)
Battery Life: About 50 hrs. (alkaline battery)
Operating Temperature: 0 to 40°C (32 to 104°F)
Operating Humidity: 10 to 90% RH
Storage Temperature: -10 to 60°C (14 to 140°F)
Storage Humidity: 10 to 75% RH
Dimensions: 210(L) x 55(W) x 32(H) mm
Weight: 230g (including battery)
IIncludes: Batteries and carrying case
Optional Accessories: Tripod (model BS-6)

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Instrument Description

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1. Windscreen
If you operate at wind speeds over 10m/sec, please put protective
accessories in front of the microphone.
2. Display
3. Power ON/OFF Button
Turn the meter power ON/OFF
4. Backlight Button
Turn the display backlight ON/OFF
5. A-Weighting/C-Weighting Select Button A/C
A: A-Weighting. For general sound level measurements.
C: C-Weighting. For checking the low frequency content of noise.
(If the C-Weighted level is much higher than the A-Weighted level,
then there is a large amount of low-frequency noise)
6. Time Weighting Select Button F/S
F(Fast Response): For normal measurements (fast varying noise)
S (Slow Response): For checking average level of  uctuating noise
7. Level Range Select Button Lo/Hi
LO: 30~100dB; HI: 60~130dB
When “OVER” is indicated, the meter automatically switches to the
other measurement range.
SYMBOL FUNCTION
LCD 4-digits
MAX Max. value hold
OVER Over range
F Fast response
S Slow response
A A-weighting
C C-weighting
LO Low range
HI High range
BAT Low battery

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8. MAX/HOLD Button MAX/HOLD
The MAX Hold position is used to measure the maximum level of
sounds. The maximum measured level is updated continuously.
Pressing the button a second time will release the maximum hold
function and allow another measurement.
The Data HOLD function freezes the reading on the display.
Data HOLD Button: Press and hold the button for 2 seconds to turn
the Data HOLD function on or off.
9. Microphone
1/2-inch electret condenser microphone
10. Battery Cover
Operating Precautions
1. Wind blowing across the microphone will bring additional extraneous
noise. If using the instrument in the presence of wind, it is recom-
mended to put the windscreen on the microphone so as not to pick
up undesirable signals.
2. To achieve more accurate measurements, use an extension cable to
separate the microphone from the main body so that the effect of
unexpected sound reection can be eliminated.
3. Calibrate the instrument before operation if the instrument has not
been in use for a long period of time or was last operated under
extreme conditions.
4. Do not store or operate the instrument in high temperature and high
humidity environments.
5. Keep microphone dry and avoid severe vibrations.
6. When not in use, please take the battery out and keep the instrument
in a low humidity environment.

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Measurement Procedures
1. Turn on power and select the desired response time and weighting.
If the sound source consists of short bursts or only catching sound
peak, set response to FAST. To measure average sound, use the
SLOW setting.
Select A-weighting for general noise sound level and C-weighting for
measuring sound level of acoustic material.
2. Select desired level.
3. Hold the instrument comfortably in hand or x on a tripod and point
the microphone at the suspected noise source, the sound pressure
level will be displayed.
4. When MAX (maximum hold) mode is chosen. The instrument captures
and holds the maximum noise level for a long period using any of the
time weightings and ranges.
5. When HOLD (data hold )mode is chosen.The hold function freezes the
reading in the display. Press the HOLD button momentarily to activate
or to exit the HOLD function.
6. Turn OFF the instrument and remove and remove battery when not in
use.
Calibration Procedures
Using a standard Acoustic Calibrator (94dB, 1kHz Sine wave)
1. Make the following function switch settings.
Display: dB, A, Hi or Lo, F
Function: A-Weighting
Response Time: Fast
Level Range: 30 to 100dB (Lo) or 60 to 130dB (Hi)
Measurement Mode: MAX Hold and DATA Hold mode function disable.
2. Insert the microphone housing carefully into the insertion hole of the
calibrator.
3. Open battery cover and remove the battery to adjust the CAL94dB
potentiometer of the unit. The level display will indicate the desired
level.

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Battery Replacement
1. Battery Loading: Open the battery cover and install a 9-Volt battery
in the battery compartment.
2. Battery Replacement: When the battery voltage drops below the
operating voltage, “BAT” appears in the display and the existing
battery should be replaced with a new one.
For service on this or any other REED product or information on other
REED products, contact REED Instruments at [e-mail].

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