When it comes to construction site compliance, environmental noise monitoring, and community impact management, accuracy is everything. And in the world of acoustic monitoring, not all sound level meters are created equal.
At Control Hire, we offer Class 1 noise monitors for hire and sale. They give infrastructure, civil, tunnelling and demolition projects precise noise data they can stand behind.
What Is Class 1 Noise Monitoring?
Noise monitors are classified under IEC 61672-1 as either
- Class 1 (precision grade)
- Class 2 (general-purpose).
Both classes are built to the same design goals. The difference is accuracy. The standard’s acceptance limits for Class 2 are equal to or wider than those for Class 1, so a Class 1 meter has to stay within tighter tolerances.
How Does a Sound Level Meter Work?
A sound level meter’s microphone turns changes in air pressure into an electrical signal. The meter then applies frequency weighting networks and a time weighting before it reports the level in decibels:
- A-weighting approximates the human ear. It is the default for most environmental noise measurement.
- C-weighting is used for peak and some low-frequency measurements.
- Z-weighting is a flat, unweighted response.
- Time weightings are Fast (125 ms), Slow (1 s) and Impulse.
The class applies to the whole instrument, microphone included. According to its spec sheet, Control Hire’s Noise Level Monitor uses a MEMS microphone, covers a frequency range of 10 Hz to 20 kHz and offers A, B, C and Z frequency weightings.
Class 1 vs Class 2 Sound Level Meters
| Specification / use case | Class 2 | Class 1 | What it means for your project |
| Measurement accuracy (IEC 61672-1) | Acceptance limits equal to or wider than Class 1 | Tighter acceptance limits | Higher precision. Tolerances vary by frequency, so ask your acoustic consultant which limits apply to your measurements. |
| Frequency range | Varies by instrument, so check the spec sheet | Varies by instrument, so check the spec sheet. Control Hire’s Noise Level Monitor covers 10 Hz to 20 kHz. | Make sure the meter covers the frequencies your assessment needs, particularly where low-frequency noise is expected. |
| NSW licence or consent compliance (construction, tunnelling, civil works) | Not accepted, unless the licence or consent sets its own method | Required under the NSW EPA Approved Methods | Check your consent and licence conditions before monitoring starts. |
| NSW road and rail projects | Not accepted for compliance measurements under the Approved Methods | Required for compliance measurements under the Approved Methods | The Approved Methods supplement the NSW Road Noise Policy and Rail Infrastructure Noise Guideline. |
| Environmental assessments (EIA/EIS) | Only where the assessment method allows it | Required where the approval or assessment requirements reference the NSW Approved Methods | Confirm the measurement method in your assessment requirements. |
| Noise and vibration management plans and council conditions | Only where the plan or conditions allow it | Where the plan or conditions specify it | Use the class your plan, consent or council conditions specify. |
| Queensland and Victorian projects | Depends on your conditions | Depends on your conditions | Check your environmental authority, development approval, permit or contract. |
| Field calibrator | Must match the meter’s class (NSW) | Must match the meter’s class (NSW) | Ask for a calibrator of the same class with every hire. |
If you’re submitting a Noise and Vibration Management Plan (NVMP) or responding to EPA or council conditions, check which class of meter they specify. In NSW, the EPA’s Approved Methods for the Measurement and Analysis of Environmental Noise (January 2022) set the rule for measurements used to show compliance with a licence or consent. Those measurements must be based on a Class 1 sound level meter unless the licence or instrument sets its own method.
Do All Australian States Require Class 1?
Requirements depend on your jurisdiction and your project’s approval conditions, so check both. As at 15 October 2026:
- NSW: Compliance measurements under the Approved Methods must use a Class 1 meter. They must also be made by a competent person, for example someone qualified for member grade of the Australian Acoustical Society. The Interim Construction Noise Guideline (2009) still applies where licence or consent conditions refer to it. Read more in our guide to construction noise regulations in NSW.
- Queensland: The Noise Measurement Manual (version 4.01, March 2020) references AS/NZS IEC 61672.1:2019. It requires meters and calibrators to be calibrated by a NATA-accredited laboratory, with field checks before and after each set of measurements. Your environmental authority, development approval or licence sets the instrument requirements for your site.
- Victoria: Victoria has its own environment protection framework. Some EPA Victoria guidance specifies Class 1 meters, such as its guideline for assessing noise from residential equipment. For construction, check your permit, planning and contract conditions.
For site-specific advice, speak with an acoustic consultant or Control Hire’s acoustic and vibration team.
Class 1 Monitoring vs Workplace Noise Exposure
Environmental noise monitoring and workplace noise monitoring answer different questions. A boundary monitor shows what neighbours and sensitive receivers are hearing. It doesn’t measure an individual worker’s noise exposure.
Under the model WHS laws, the workplace exposure standard for noise is an LAeq,8h of 85 dB(A) or an LC,peak of 140 dB(C). Exposure is determined in line with AS/NZS 1269.1. Victoria has its own OHS laws, so check WorkSafe Victoria’s guidance there. If workers may be exposed to excessive or harmful noise levels, ask a competent person, such as an occupational hygienist, about personal noise exposure monitoring.
Why Control Hire offers Class 1 Noise Monitoring Equipment
Control Hire is trusted by Tier 1 contractors, councils, and consultants to deliver environmental noise monitoring systems that meet or exceed compliance requirements.
We supply:
- Class 1 sound level monitors (IEC 61672 Class 1, per the product spec sheet)Â
- Real-time cloud-connected monitoring, with email and SMS alerts and historical noise data to help you identify trendsÂ
- Construction Noise and Vibration Management Plans (CNVMPs)
- Acoustic and vibration consulting
- Installation and ongoing support
With our in-house team, you get more than equipment. We support you from planning your monitoring through to installation on site.
More Than Monitoring: Full-Service Noise Control
Control Hire provides integrated solutions for temporary construction noise control, including:
- Class 1 Noise Monitors
- The Noise Control Wall – 85% sound absorption, Australian-made, eco-friendly modular solution
- Sound blankets & Folding Frames
- Fan & exhaust silencers
- Cutting Stations/Acoustic Enclosures
- Onsite noise assessments, Noise & Vibration Management Plans
All our systems are backed by engineering certification and align with local EPA guidelines and council permit conditions.
Why This Matters for Your Project
- Defensible data: Measurements made with the class of meter your conditions specify are easier to rely on if results are questioned.
- Community confidence: Real-time alerts help your team act early when noise levels rise.
- Tender advantage: Show you can meet environmental monitoring specifications on major projects.
- Data accuracy: Make informed decisions with confidence.
Hire Class 1 Noise Monitors from Control Hire
Whether you’re managing a large-scale infrastructure build or a short-term civil job, Control Hire supplies Class 1 monitoring systems and acoustic support from our Sydney, Melbourne and Brisbane branches.
- Class 1 monitoring equipment
- Real-time data and reporting
- In-house acoustic and vibration engineersÂ
- Hire and sale options
FAQs
Is a Class 2 sound level meter ever acceptable?
It can be, where your licence, approval or the applicable guideline allows it. In NSW, compliance measurements under the EPA’s Approved Methods must be based on a Class 1 meter. Check your conditions or ask your acoustic consultant.
Does a Class 1 meter guarantee compliance?
No. The class describes the instrument’s accuracy. Compliance also depends on where and how measurements are taken, calibration, the descriptors recorded and who analyses the results.
Can a site noise monitor measure workers’ noise exposure?
Not on its own. Worker exposure is assessed against the WHS exposure standard using the methods in AS/NZS 1269.1, usually by a competent person such as an occupational hygienist.