Sound Level Meters
Optimus+ Environmental Sound Level Meter
The Optimus+ Environmental Sound Level Meter has been specifically designed for measuring and monitoring exposure to noise pollution and environmental noise sources.
- Periodic LAeq and Ln values (e.g. L10, L90), LMax and LMin
- Easy to use, measures all parameters simultaneously
- Choose a Class 1 or Class 2 model
- VoiceTag audio notes and audio recording
- Available with tonal noise detection, 1:1 octaves or 1:3 octaves
Optimus+ Environmental Sound Level Meter
Environmental noise level measurement made easy
The top-of-the-range Optimus+ Environmental Sound Level Meter has been specifically designed as an environmental noise meter and is perfect for measuring and monitoring exposure to noise pollution and environmental noise sources, including construction sites, windfarms and industrial operations.
Available as either a Class 2 or Class 1 sound level meter, built to IEC 61672, the Optimus+ Environmental sound level meter provides everything you need to measure both occupational and environmental noise, to the fullest extent.
Capturing the full range of sound parameters simultaneously, there’s no other noise measuring instrument you need to measure and monitor exposure to environmental noise.
All Optimus+ Environmental sound level meters are integrating data logging instruments, providing noise data such as sound pressure level (SPL), Leq and Peak and TWA/Dose. Optional measurement parameters include 1:1 and/or 1:3 octave band filters, tonal noise detection, Ln values, and on-screen NR/NC curves.
Need to measure noise outside?
The Optimus+ Environmental Sound Level Meter complies with UK, EU, and international standards, works worldwide, and integrates with weatherproof outdoor kits for versatile noise monitoring in any conditions.
You can choose an outdoor kit with or without a modem for unattended measurements.
VoiceTag | Audio Note Recording
Each of our data logging Optimus+ Sound Level Meters feature VoiceTag audio note recording, increasing the ease with which your NoiseTools database can be organised.
Before each measurement, simply speak into the microphone to provide additional information such as the location of your reading. Once your measurement data is downloaded to NoiseTools, these audio notes are automatically converted into text.
Acoustic Fingerprint | Audio triggering, recording & alerts
Each of our Optimus+ Environmental Sound Level Meters feature Acoustic Fingerprint technology, allowing you to automatically record and store audio by configuring a set of detection templates and rules.
You can store audio recordings as either 96kHz/32bit quality, 48kHz/24bit quality, or as standard 16kHz/16bit bit quality which can be used for replay and source identification.
When used with the Outdoor Environmental Noise Kit with Remote Access, the Optimus+ Environmental Sound Level Meter can communicate remotely and provide both data download and live noise information to NoiseTools.
GPS location data is also provided allowing noise measurements to be stamped with the location, date and time.
Pattern Approval
The Class 1 variant of this Environmental sound level meter has PTB Pattern Approval, and LNE Pattern Approval. See the Downloads tab for our certificate.
Pattern Approval is a method where a test laboratory such as the PTB tests an instrument against a set of standard tests to ensure that it meets the performance claims of the manufacturer.
Applicable Standards
- IEC 61672-1:2013 Class 1 or Class 2
- IEC 61672-1:2002 Class 1 or Class 2 Group XIEC
- IEC 60651:2001 Type 1 I or Type 2 I
- IEC 60804:2000 Type 1 or Type 2
- IEC 61252:1993 Personal Sound Exposure Meters
- ANSI S1.4 -1983 (R2006), ANSI S1.43 – 1997 (R2007)
- ANSI S1.25:1991
- 1:1 & 1:3 Octave Band Filters to IEC 61260 & ANSI S1.11-2004
Type Approvals for Class 1 Instruments
- LNE-25387-1 IEC 61672-1:2013
- NF EN 61672-1:2014
- IEC 61260:1996
- NF EN 61260:1996
- LNE-25387-0
- EN 61672-1:2003
- PTB-1.53-4052960 DIN EN 61672-1:2003-10
- DIN EN 61672-2:2004-08
- DIN 45657:2005-03
- Applus+ 02-001-B-62/13-R
- UNE-EN 61672-1:2005
Microphone
Class 1 MK:224 pre-polarized, Class 2 MK:216 pre-polarized
Microphone Preamplifier
MV:200 Removable Preamplifier (All versions)
Total Measurement Range:
20dB to 140dB RMS Single Range
Noise Floor: <18dB(A) Class 1, <21dB(A) Class 2
Frequency Weightings
- RMS & Peak : A, C, & Z Measured Simultaneously
- Frequency Bands: 10 x 1:1 Octave Bands (31.5Hz to 16kHz, A, B & C variants)
- Frequency Bands: 36 x 1:3 Octave Bands Measured (6.3Hz to 20kHz, B & C variants)
- Frequency Bands: 33 x 1:3 Octave Bands Displayed (12.5Hz to 20kHz, B & C variants)
- Additional Metrics: LAeq LF (20Hz to 200Hz) & Leq LF (20Hz to 200Hz)
Time Weightings
Fast, Slow & Impulse Measured Simultaneously
Display
High resolution OLED display. Ambient light sensor & illuminated keypad
Memory
8GB with 32GB factory fit option
AuditStore
Measurement verification data stored in secure memory
Time History Data Rates (Global settings)
10ms, 62.5ms, 125ms, 250ms, 1/2 sec, 1 sec, 2 sec (User selectable)
VoiceTag Audio Recording
Up to 30 seconds of audio notes with each measurement
Bluetooth
BLE compatible with Android and iOS devices.
Cirrus mobile applications available from Google Play and the App Store
Acoustic Fingerprint Audio Recording
Off, Manual, Threshold Triggered, Advanced Trigger
User options:
- Studio Quality – 96kHz/32bit WAV format
- Standard quality – 16kHz/16bit WAV format
- Pre-Trigger function
Integrators
Three simultaneous “virtual” noise meters. Integrator 1 is preset to Q3 for Leq functions. Integrators 2 & 3 can be configured with the following:
- Exchange Rate: 3, 4 or 5 dB
- Threshold: 70dB to 120dB (1 dB steps)
- Time Weighting: None or Slow
- Criterion Level: 70dB to 120dB (1 dB steps)
- Criterion Time: 1 to 12 hours in 1 hour steps
Integrator Quick settings
- EU, OSHA HC & OSHA NC, OSHA HC & ACGIH, MSHA HC & MSHA EC, Custom 1 & Custom 2
- Ln Statistical Values
- 14 independent statistical Ln values calculated from 1/16th LAF
- 7 preset to L1.0, L5.0, L10.0, L50.0, L90.0, L95.0 & L99.0
- 7 user defined Ln values. CR:172C & CR:171C allow for an additional 14 Ln values with independent time and frequency weighting.
Measurement control
- Measurement control with user selectable duration of manual, 1 min, 5 min, 10 min, 15 min,30 mins, 1 hour, Lden
- Automatic Synchronisation & Repeat
- Pause & Back Erase with user selectable duration
Dimensions
Size: 283mm x 65mm x 30mm
Weight: 300gms/10oz
Batteries
4 x AA Alkaline
Battery life
Typically 12 hours with Alkaline AA
Typically 20 hours with Lithium AA Non-Rechargeable
Battery life is dependent upon the battery type, quality & screen brightness
Connections
- USB Type B to PC
- AC & DC Output via ZL:174 (2 x Phono, 1m)
- Multi-pin IO for external power via ZL:171 cable (2.1mm socket)
- External Power: 5v-15v via MultiIO socket via ZL:171 cable (2.1mm socket)
- Tripod Mount
- 1/4″ Whitworth socket
Case
Material: High Impact ABS-PC with soft touch back & keypad
Environmental
Temperature: Operating -10°C to +50°C, Storage -20°C to +60°C
Humidity: Up to 95% RH Non Condensing
Electromagnetic performance
- IEC 61672-1:2002 & IEC 61672-2:2003
- IEC 61672-1:2013 & IEC 61672-2:2013
- Except where modified by EN 61000-6-1:2007 & EN 61000-6-1:2007
Language options
English, French, German, Spanish. Other language options may be available
Software Support
NoiseTools Download, Configuration & Analysis software supplied as standard. Compatible with Microsoft Windows XP, Vista, 7 & 8 (32bit & 64bit)
Displayed Functions
- LXY, LXYMax, LXYMin, LXeq, LCPeak, LAPeak, LZPeak, LCeq-LAeq, LXE, LAIeq
- Graph of Short LAeq, LCPeak
- Integrators 2 & 3: TWA, Dose%, Est Dose%
- Real-Time 1:1 Octave Bands (Graphical & Numeric)
- Real-Time 1:3 Octave Bands (Graphical & Numeric)
- Tonal Noise Detection in 1:3 Octave Bands
- NR & NC values & curves
- Measurement Run Time
- Integrators 2 & 3: TWA, Dose%, Est Dose%
- Leq LF (20Hz to 200Hz)
- 28 Statistical Ln values
Stored Functions
- LXYMax & Time History of LXYMax
- LAeq, LCeq, LZeq, LCPeak, LZPeak, LAPeak, LAIeq
- Time History of LAeq, LCeq, LZeq, LCPeak, LZPeak, LAPeak, LAIeq
- Integrators 2 & 3: LAVG, TWA. %Dose
- Time History of LAVG
- 1:1 & 1:3 Octave Bands:Overall Leq & Leq Time History for each band, NR & NC values & curves
- Tonal Noise Detection in 1:3 Octave Bands
- Ln Values: 28 independent statistical values
- Audio recording during measurement
- where x=A ,C ,Z; y= F, S, I
- Other functions may calculated by the NoiseTools software and displayed on download.
Optimus+ Industrial Sound Level Meter
The Optimus+ Industrial Sound Level Meter captures all essential noise level data simultaneously. By adding Leq values, you can ensure your occupational noise surveys will be comprehensive and robust.
- Optional quick settings for occupational noise measurements: EU, OSHA, ACGIH, and MSHA standards
- Easy to use, measures all parameters simultaneously
- Choose a Class 1 or Class 2 model
- Large colour display so the data is easy to read
- Available as an octave band sound level meter with NR/NC curves
Optimus+ Industrial Sound Level Meter
Basic noise measurements made easy
The standard Optimus+ Industrial Sound Level Meter is capable of measuring the maximum noise level during a session, and provides simple and easy-to-understand data, including frequency weightings and time history.
Most suited for applications where only basic noise level data is required, these models can record the sound pressure level (SPL), maximum sound level (LMax) in decibels, which refers to the loudest recorded noise level during a period of data capturing. The Optimus+ Industrial allows for data logging of the sound levels measured over a user-defined period of time.
This data will give you a basic understanding of the noise levels where you are measuring, and will allow you to identify any particular noise hotspots.
Occupational noise level measurement made simple
The Optimus+ Industrial Sound Level Meter with Leq Values makes noise level measurements incredibly easy and straightforward, saving you time while capturing all essential noise level data simultaneously. This instrument captures sound pressure level (SPL), time weighted and frequency weighted values at the press of a single button.
By measuring every parameter simultaneously, you can be sure that your occupational noise survey will be comprehensive and robust, providing the level of detail required for making better-informed decisions and reporting to key stakeholders within your organisation.
Remote Operation
Sometimes it’s not possible to hold the meter whilst taking measurements, this might be due to location, the noise level itself, or the length of time you want to measure for.
The Optimus+ Industrial sound level meter range includes Bluetooth connectivity to help solve this; with the addition of the dBActive smartphone app, you can easily operate your sound level meter from a short distance away.
VoiceTag Audio Note Recording
Each of our data logging Optimus+ Industrial Sound Level Meters feature VoiceTag audio note recording, increasing the ease with which your NoiseTools database can be organised.
Before each measurement, simply speak into the microphone to provide additional information such as the location of your reading. Once your measurement data is downloaded to NoiseTools, these audio notes are automatically converted into text.
Pattern Approval
The Optimus+ Industrial Sound Level Meter with Leq Values and with Octave Bands both have LNE Pattern Approval. See the Downloads tab for our certificate.
Pattern Approval is a method where a test laboratory such as the LNE tests an instrument against a set of standard tests to ensure that it meets the performance claims of the manufacturer.
Applicable standards*1
IEC 61672-1:2013 Class 1 or Class 2*1
IEC 61672-1:2002 Class 1 or Class 2 Group X*1
IEC 60651:2001 Type 1 I or Type 2 I
IEC 60804:2000 Type 1 or Type 2
IEC 61252:1993 personal sound exposure meters
ANSI S1.4 -1983 (R2006), ANSI S1.43 – 1997 (R2007), ANSI S1.25:1991
IEC 61260:1996 & ANSI S1.11-2004
DIN 45657:2005-03
Microphone
Class 1 MK:224/MK:229 pre-polarized, Class 2 MK:216 pre-polarized
Microphone preamplifier
MV:200 removable preamplifier (all versions)
Total measurement range:
20dB to 140dB RMS single range
Noise floor: <18dB(A) Class 1, <21dB(A) Class 2
Frequency weightings
RMS & peak: A, C, & Z measured simultaneously
Frequency bands: 10 octave bands (31.5Hz to 16kHz)
Time weightings
Fast, Slow & Impulse measured simultaneously
Display
High resolution display. Ambient light sensor and illuminated keypad
Memory
8GB, 32GB factory-fit option
AuditStore
Measurement verification data stored in secure memory
Time history data rates (global settings)
10ms, 62.5ms, 100ms, 125ms, 250ms, 1/2 sec, 1 sec, 2 sec (user
selectable)
VoiceTag audio recording
Up to 30 seconds of audio notes with each measurement
Integrators
Three simultaneous “virtual” noise meters. Integrator 1 is preset to Q3 for
Leq functions. Integrators 2 & 3 can be configured with the following:
Exchange rate: 3, 4 or 5 dB
Threshold: 70dB to 120dB (1 dB steps)
Time weighting: None or Slow
Criterion level: 70dB to 120dB (1 dB steps)
Criterion time: 1 to 12 hours in 1 hour steps
Integrator quick settings
EU, OSHA HC & OSHA NC, OSHA HC & ACGIH, MSHA HC & MSHA EC, Custom 1 & Custom 2
Measurement control
Pause & back erase with user-selectable duration
Dimensions
Size: 283mm x 65mm x 30mm
Weight: 300gms/10oz
Batteries
4 x AA alkaline
Battery life
Typically 12 hours with alkaline AA
Typically 20 hours with lithium AA non-rechargeable. Battery life is dependent upon the battery type, quality and screen brightness
Connections
USB Type B to PC
AC & DC output via ZL:174 (2 x Phono, 1m)
Multi-pin IO for external power via ZL:171 cable (2.1mm socket)
External power: 5v-15v via MultiIO socket via ZL:171 cable (2.1mm socket)
Tripod mount
1/4” Whitworth socket
Case
High impact ABS-PC and soft touch back and keypad
Environmental
Operating
temperature -10°C to +50°C
Storage
temperature -20°C to +60°C
Humidity Up to 95% RH non-condensing
Electromagnetic performance
IEC 61672-1:2002, IEC 61672-2:2003, IEC 61672-1:2013 & IEC 61672-2:2013
Except where modified by EN 61000-6-1:2007 & EN 61000-6-1:2007
Language options
English, French, German, Spanish, Italian. Other language options may be available
Software support
NoiseTools analysis software supplied as standard. Compatible with Microsoft Windows 7, 8 & 10 (32bit & 64bit)
Bluetooth
BLE compatible with Anrdoid and iOS devices
Cirrus mobile applications available from Google Play and the App Store.
All specifications, features and values are typical and are subject to change without notice.
Measurement functions
CR:152B & CR:151B
Displayed functions
LXY, LXYMax, LXYMin
Measurement run time
Stored functions
LXYMax & time history of LXYMax
CR:162B & CR:161B
Displayed functions
LXY, LXYMax, LXYMin,,LXeq, LCPeak, LZPeak, LCeq-LAeq, LXE, LAIeq
Graph of short LAeq, LCPeak
Measurement run time
Integrators 2 & 3: TWA, dose%, est dose%
Stored functions
LXYMax & time history of LXYMax
LAeq, LCeq, LZeq, LCPeak, LZPeak, LAPeak
Time history of LAeq, LCeq, LZeq, LCPeak, LZPeak, LAPeak, LAIeq
Integrators 2 & 3: LAVG , TWA. %dose
Time history of LAVG
CR:162C & CR:161C
Displayed functions
LXY, LXYMax, LXYMin, LXeq, LCPeak, LZPeak, LCeq-LAeq, LXE, LAIeq
Graph of short LAeq, LCPeak
Measurement run time
Integrators 2 & 3: TWA, dose%, est dose%
Real-time octave band filters
NR & NC values & curves
Stored functions
LXYMax & time history of LXYMax
LAeq, LCeq, LZeq, LCPeak, LZPeak, LAPeak
Time history of LAeq, LCeq, LZeq, LCPeak, LZPeak, LAPeak, LAIeq
Integrators 2 & 3: LAVG , TWA. %dose
Time history of LAVG
Octave Bands: Overall Leq & Leq Time History for each band
NR & NC values & curves
Measurement run time
Time & date of measurement start
where x= A ,C or Z
y= F, S or I
Other functions may calculated by the NoiseTools software and displayed on download.
Notes
1. Please contact Cirrus Research plc for details of the standards and approvals that are available on specific instrument types.
2. For details of the displayed and stored parameters, please refer to the optimus user manual for full specifications.
All specifications, features and values are typical and are subject to change without notice.
Safety Officer’s Noise Measurement Kit
The Safety Officer’s Noise Measurement Kit contains everything you need for compliant occupational or environmental noise assessments
- A complete noise measurement solution for occupational or environmental noise
- Combine any Optimus+ Sound Level Meter with up to 5 doseBadge noise dosimeters
- Single robust carry case for all the components & accessories
- Includes the NoiseTools software for download, reporting & analysis
Safety Officer’s Noise Measurement Kit
The Safety Officer’s Noise Measurement Kit combine your choice of Optimus+ Sound Level Meter with any of our doseBadge Personal Noise Dosimeters to create a Complete Noise Measurement Kit. The Safety Officer’s Noise Measurement Kit includes all of the accessories you need for each instrument, supplied together in a single robust carry case.
Optimus+ Sound Level Meters
The Optimus+ Sound Level Meters use the very latest technology to provide instruments that are simple to use whilst giving you the measurement information that you need to make an effective noise measurement. Choose from the Optimus+ Industrial Sound Level Meter or the Optimus+ Environmental Sound Level Meter to create Safety Officer’s Noise Measurement Kit that suits your needs.
doseBadge Personal Noise Dosimeters
The addition of doseBadge Noise Dosimeters allows you to track the noise exposure of individuals throughout their shift, giving you a Lep,d. Workers wear the doseBadge on their shoulders to determine their individual levels of exposure so that you can prescribe the correct level of hearing protection they need.
All of our doseBadges feature data logging, allowing you to download all of your measurements to NoiseTools for detailed analysis and the production of compliant noise at work assessments. Choose from our full range of doseBadge Personal Noise Dosimeters to create Safety Officer’s Noise Measurement Kit that suits your needs.
Vehicle Noise Measurement Kit
Our Vehicle Noise Measurement Kit includes everything you need to measure stationary vehicle noise, including your choice of Optimus+ Sound Level Meter, trigger button, and measurement template.
- Includes everything needed to make hassle-free vehicle noise measurements
- Choose from our range of Optimus+ Sound Level Meters
- Distance template to easily position your microphone
- Remote trigger button allows single-person operation
- Undertake measurements to ISO 5130-2019
Vehicle Noise Measurement Kit
The perfect solution for monitoring and measuring vehicle noise
Designed to be used in workshops, garages and test laboratories alike, the Vehicle Noise Measurement Kit is a robust kit that is simple to operate whilst providing the measurements needed for stationary vehicle measurements of exhausts.
Conforms to vehicle noise regulations ISO 5130-2019
The kit uses your choice of Optimus+ Sound Level Meter and no matter which one you choose, the sound level meter measures all noise parameters simultaneously and then automatically calculates the average noise level from three readings. This is what is required to conform to vehicle noise regulations ISO 5130-2019 for the measurement of sound pressure level emitted by stationary road vehicles.
Single person operation
Vehicle Noise Measurement Kit includes a microphone extension cable and remote trigger button, this means vehicle exhaust noise measurement can be set up and operated by a sole person. The operator sits in the car, truck or other vehicle and controls the engine speed/revs whilst pressing the trigger button to start and stop each of the three measurements required.
Standards
ISO 5130:2007
§29 StVZO
Recommended sound level meter
Optimus+ Red
(all Optimus+ variants can be used)
Measurement data
LArep dB
Three LAFMax readings taken when
measurement trigger is pressed
Microphone cable length
5 meters
Measurement trigger cable length
1 meter (longer length available on request)
Display
High-resolution display.
Ambient light sensor
Illuminated keypad
Battery life
Typically 12 hours with alkaline AA batteries
Typically 20 hours with lithium AA non-rechargeable
CR310 Low-Cost Integrating Decibel Meter
The CR:310 low-cost integrating decibel meter is ideal for providing noise measurement data, and assisting you in carrying out basic noise-at-work assessments
- Class 2 integrating sound level meter (meets IEC 61672-1:2013)
- Measure Sound Pressure Level (SPL) and Maximum Sound Level (LMax)
- Leq, and Leq8h
- A and C frequency weightings
- Basic workplace noise assessments
The Cirrus Research Low-Cost Integrating Decibel Meter
The CR:310 is an integrating decibel meter ideal for simple noise measurements and basic noise at-work measurements. In addition to measuring the maximum sound level (LMax), CPeak, and the sound pressure level (SPL), the CR:310 provides average noise level data (Leq) and the overall dose values (Leq8h), this allows it to be used for basic workplace noise assessments.
The decibel meter also displays A and C frequency weightings, as well as Fast and Slow time weightings which other basic sound level meters available on the market cannot. The CR:310 displays the Leq for one measurement, using the start/stop button on the instrument. You can also send the measurements directly to a portable printer (sold separately).
Applicable Standards:
IEC 61672-1:2013 Class 2
Measurement Range:
30dB (A) to 130dB (A)
40dB (C) to 130dB (C)
Frequency Weightings:
A and C
Time Weightings:
Fast (F) and Slow (S)
Display Functions:
Normal, Maximum, Minimum, C peak
Measurement Functions:
LAF, LAS, LCF, LCS, LCpk
Leq (CR:310), LEq8h (CR:310)
Noisefloor:
< 25dB (A) and 35dB (C)
Display Flags
Threshold Limit, Overload, Under-range
Auto Calibration Range:
±4.5dB
Reference Point:
94dB (1kHz), 92.9dB (8kHz)
Setting Time:
60s
Display:
Backlit 128×64 LCD，resolution 0.1 dB.
Resolution:
0.1dB
Electrical Inputs:
5V power in via mini USB
Power:
2 x AA/LR6 1.5V batteries
Or
5V DC via Mini USB
Battery Life:
24hrs
Microphone:
½˝ pre-polarised electret condenser type HY:205
Operating Temperature:
0°C to +40°C
Operating Humidity:
25% to 90%
Atmospheric Pressure:
65 kPa to 108kPa
Storage Temperature:
-20°C to +60°C
Dimensions:
215mm×68mm×32 mm
Weight:
220g（including battery)
Electrical Outputs:
AC (Tip 3.5mm jack) and DC (middle 3.5mm jack)
DC Output:
voltage 15mV/dB, range 450mV to 1950mV
AC Output:
RMS 2V
CR308 Low-Cost Decibel Meter
The CR:308 low-cost decibel meter is ideal for providing simple noise measurement information as part of noise level testing applications
- Simple to use Class 2 meter (meets IEC 61672-1:2013 Class 2)
- Measure Sound Pressure Level (SPL) and Maximum Sound Level (LMax)
- A and C frequency weighting
- Quick and easy hassle-free sound checks
The Cirrus Research Low-Cost Decibel Meter
The CR:308 is a basic sound level meter that is perfect when all you need is access to simple noise measurement information. The meter is capable of measuring the maximum sound level (LMax) and the sound pressure level (SPL), and is ideal for simple applications, such as alarm testing, spot checks, and other noise level testing applications.
The CR:308 includes an adjustable noise level threshold alarm so you can be alerted when noise exceeds a set level.
The Cirrus Research CR:308 low-cost decibel meter is suitable for noise measurement across multiple sectors and meets current international standards for noise measurement instrumentation including IEC 61672-1:2013 Class 2.
Applicable Standards:
IEC 61672-1:2013 Class 2
Measurement Range:
30dB (A) to 130dB (A)
40dB (C) to 130dB (C)
Frequency Weightings:
A and C
Time Weightings:
Fast (F) and Slow (S)
Display Functions:
Normal, Maximum, Minimum, C peak
Measurement Functions:
LAF, LAS, LCF, LCS, LCpk
Leq (CR:310), LEq8h (CR:310)
Noisefloor:
< 25dB (A) and 35dB (C)
Display Flags
Threshold Limit, Overload, Under-range
Auto Calibration Range:
±4.5dB
Reference Point:
94dB (1kHz), 92.9dB (8kHz)
Setting Time:
60s
Display:
Backlit 128×64 LCD，resolution 0.1 dB.
Resolution:
0.1dB
Electrical Inputs:
5V power in via mini USB
Power:
2 x AA/LR6 1.5V batteries
Or
5V DC via Mini USB
Battery Life:
24hrs
Microphone:
½˝ pre-polarised electret condenser type HY:205
Operating Temperature:
0°C to +40°C
Operating Humidity:
25% to 90%
Atmospheric Pressure:
65 kPa to 108kPa
Storage Temperature:
-20°C to +60°C
Dimensions:
215mm×68mm×32 mm
Weight:
220g（including battery)
Electrical Outputs:
AC (Tip 3.5mm jack) and DC (middle 3.5mm jack)
DC Output:
voltage 15mV/dB, range 450mV to 1950mV
AC Output:
RMS 2V