Optimus+ Occupational Sound Level Meter

Sound Level Meters

The Optimus+ Occupational Sound Level Meter captures all essential noise level data simultaneously, ensuring your occupational noise survey will be comprehensive and robust.

  • Quick settings for occupational 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
Instrument class *

Choose the Class of meter you would like

Meets IEC 61672-1:2013

Meets IEC 61672-1:2013

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Tag: Sound Level Meters


Optimus+ Occupational Sound Level Meter

Occupational noise level measurement made easy

The Optimus+ Occupational Sound Level Meter makes noise level measurements incredibly easy and straightforward, save you time while capturing all essential noise level data simultaneously. The 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.

All of your measurement data can be displayed on the large colour display, so you can immediately see if there are any occupational noise problems in your workplace. With large buttons and minimal controls, the Optimus+ Occupational Sound Level Meter allows you to easily navigate screens and see the data you need during measurements.

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+ Red 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+ 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 Class 1 variant of this meter has 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. Find out more here.

The Optimus+ Occupational Sound Level Meter Range

The Optimus+ Occupational Sound Level Meter is available in four models designed for various workplace noise monitoring activities. Upgrade this instrument at any time by contacting our team of experts.
Noise at Work Sound Level Meter
Optimus+ Red

With this instrument, each required parameter will be measured simultaneously, with the large colour display showing the live measurements as they take place so you can easily see the results of your noise measurement survey.

Class 1 LNE or PTB approved models available
Minimal controls for quick and easy use
Integrating noise meter for occupational assessments
LCeq – LAeq for quick hearing protector selection
Noise at Work Sound Level Meter
Optimus+ Red with Data Logging

The Optimus+ Red with Data Logging also comes with our licence-free noise measurement analysis software, NoiseTools as standard allowing you to create quick and compliant noise assessment reports.

Class 1 LNE or PTB approved models available
VoiceTag audio note recording
Data logging & licence-free analysis software
Up to 32GB of memory for sophisticated measurements
Optimus+ Red with Octave Bands

This meter offers you everything you could possibly need for compliant noise at-work assessments including 1:1 real-time octave band filters for the correct selection of hearing protectors based on the frequency content of the noise measured.

Class 1 LNE or PTB approved models available
VoiceTag audio note recording
1:1 octave bands for hearing protector selection
Up to 32GB of memory for sophisticated measurements
Optimus+ Red with NR & NC Curves

This meter goes beyond the standard features of integrating sound level meters and includes real-time 1:1 octave band filters that measure in all frequency bands at the same time; making it ideal for Noise Rating and Noise Criterion calculation.

Class 1 LNE approved model available
VoiceTag audio note recording
1:1 octave bands for NR and NC calculation
Up to 32GB of memory for sophisticated measurements
We Recommend

Occupational Noise Monitoring

Watch the product video to find out how the Optimus+ Sound Level Meter makes occupational noise assessments easier than ever


The comprehensive solution for workplace noise

The Optimus+ Occupational Sound Level Meter captures all essential noise level data simultaneously, ensuring your occupational noise survey will be comprehensive and robust.

Find out more about the importance of workplace noise monitoring and discover our top tips to get you started.

UK & EU Noise at Work Regulations

If you are working to the UK Control of Noise at Work Regulations or the EU Physical Agents (Noise) Directive, the Leq View gives you the information that you need.

The LAeq and LCPeak values are measured at the same time which allow the LEP,d (LEX,8h) and the Peak Action Levels to be determined.

The LCeq-LAeq (C-A) value is also measured which can be used to select PPE using the HML method. LAE is also measured along with LZPeak for regulations that use this rather than LCPeak.

OSHA, MSHA & Other Regulations

If you need to meet regulations such as OSHA HC & NC, MSHA HC or ACGIH, the two “virtual” noise meters in the Dose View can be quickly configured to provide you with this information.

The Quick Setup gives access to a number of preset functions including OSHA HC & NC, OSHA HC & ACGIH and MSHA HC & EC.

The custom settings can be used to choose any other setup or configuration that you may need. Once you’ve chosen the setup needed it will be stored so each time you use the meter you will have the information you need.

For the two “virtual” noise meters, the LAVG, TWA, % Dose and Estimated % Dose are displayed.

The C & D models also feature real-time octave band filters which will measure the noise in 10 different frequency bands.

The octave band measurement is made at the same time as the other measurements and includes the overall level in each band along with a time history of the bands across the measurement period.

NR & NC values & curves on screen

The D model adds NR & NC values and curves to the 1:1 octave band measurements. This information can be useful in checking the performance of HVAC systems and noise levels in rooms.

If you choose the data logging version of the Optimus Red, we’ll include our NoiseTools Noise Analysis Software so you can keep a record of your measurements. If you choose the Optimus Red with 1:1 Octave Bands, NoiseTools can also recommend hearing protection based on your data.

You can upgrade this instrument to a more advanced version of the Optimus Red or the Optimus Green at any time, future-proofing your investment.

Applicable Standards

  • IEC 61672-1:2013 Class 1 or Class 2
  • IEC 61672-1:2002 Class 1 or Class 2 Group X
  • 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 Octave Band Filters to IEC 61260 & ANSI S1.11-2004 (C & D variants)



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 Octave Bands (31.5Hz to 16kHz, C & D variants) Time Weightings

Fast, Slow & Impulse Measured Simultaneously


High resolution display. Ambient light sensor & illuminated keypad


4GB (B, C & D Versions), 32GB factory fit option


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 (B, C & D Versions)

Up to 30 seconds of audio notes with each measurement


BLE compatible with Android and iOS devices.

Cirrus mobile applications available from Google Play and the App Store


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

  • MSHA HC & MSHA EC, Custom 1 & Custom 2
  • Measurement control
  • Pause & Back Erase with user selectable duration



Size: 283mm x 65mm x 30mm

Weight: 300gms/10oz


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


  • 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



Material: High Impact ABS-PC with soft touch back & keypad


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

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, 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 ,Z; y= F, S, I
  • Other functions may calculated by the NoiseTools software and displayed on download.

Additional information

Weight 0.30 kg
Dimensions 28.3 × 6.5 × 3.0 cm

Occupational Noise

Building Acoustics

Hardware Features


Communication Interfaces




Power Supply Options

Average Operating Time

Sound Measurement Features

Applicable Standards


Type Approvals

Total Measurement Range

Frequency Weightings

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Time Weightings

, ,

Data Logging

Minimum Data Logging Interval





1:1 Octave Bands

NR/NC Curves

VoiceTag Audio Notes

Acoustic Fingerprint


Cirrus Research


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Monitoring Duration


Optimus+ Red Sound Level Meter

User Manual

Optimus+ Red Sound Level Meter

Datasheet (English)

Optimus+ Red Sound Level Meter

Datasheet (Chinese)

Optimus+ Red Sound Level Meter

PTB Certificate

Optimus+ Red Sound Level Meter

LNE Certificate

Optimus+ GPS Module

User Manual

Optimus+ GPS Module


  1. Martin Gray

    The Optimus Red boasts a high resolution colour OLED which simplifies the use of the instrument and makes viewing the noise results a lot easier

  2. Chris Wink

    The Optimus is very easy to use and very effective

  3. Nick Phillips

    There is nothing out there that can rival the Optimus Red noise level meter for its intuitive technology and accuracy

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