Products > Noise Monitors > Weatherproof Outdoor Noise Kit

Outdoor Noise Measurement Kit

Outdoor Noise Kit
Outdoor Noise Kit
Outdoor Noise Kit Outdoor Noise Kit
Outdoor noise measurement kit
3 weeks

1/3 Octave Outdoor noise measurement kit
3 weeks


  • Easily relocated
  • Weatherproof case and outdoor microphone
  • Up to 7 days unattended operation
  • Type 1 Sound Level Meter with 1/3 Octave Band option


  • Environmental noise surveys
  • Community noise assessments
  • Construction and demolition sites
  • Factory and industrial site boundary noise
  • Road traffic and other transport noise


The WPK-633 Outdoor Noise Measurement Kits are designed for applications where a meter needs to be left unattended in poor weather conditions to monitor for up to a week.

These noise measurement kits include a Sound Level Meter that was designed specifically for environmental noise measurement. The meter meets the sound level meter standards to Type 1 (Class 1) and makes all the measurements required by most such surveys, including the periodic LAeq and the statistical Ln parameters (L10, L90, etc).

sound level meter in weatherproof kit

The meter makes automatic repeating measurements, providing the tables of periodic results typically needed for this type of survey.

There are a number of meters available, but we recommend either the CEL633A1 or the CEL633C1. You can read about the differences on the Which Meter? tab. If you want a lower grade meter or don't need all the items included in the standard kits then please contact us for a custom kit quotation.

Outdoor Noise Kit Contents

The standard WPK-633A1 and WPK-633C1 kits contain the following items:

CEL 633 Sound Level Meter Usually either the CEL633A1 (Type 1, data logging) or the CEL633C1 (adds real-time 1/3 octave band filters). The meter can be removed from the kit and used hand-held for short term noise measurements.

CEL120/1 Calibrator Checks the function of the meter. Required by many noise measurement regulations.

Weatherproof Carrying Case Holds the meter, calibrator and rechargeable battery.

Rechargeable Battery To allow the meter to run unattended for at least seven days.

Insight Software To download the measurements and produce reports.

Outdoor Microphone and Extension Cable This provides protection against poor weather (rain, snow, hail) for the noise measurement microphone capsule, preamplifier and connections. A 5m (16ft) cable connects from the microphone to the case.

Windshield and Bird Spikes The windshield reduces the effect of wind on the microphone and the bird spikes discourage landing and pecking.

Tripod The microphone mounts on a standard camera tripod, so if the one included in the kit gets damaged it is easily replaced.


The sound level meter included in this kit is suitable for almost any noise measurement application, not just environmental noise, as it exceeds the requirements of most regulations such as those covering occupational noise. If you have additional applications as well as your environmental noise monitoring then these meters will usually be suitable for that too.

General Environmental Noise Survey

These kits are designed to be left unattended for up to seven days, making automatic and repeating measurements. For example, many surveys require repeating 15 minute measurements, providing parameters such as:

  • LAeq (A-weighted average sound level)
  • LAmax (maximum sound level, either Fast or Slow time weighted)
  • LAmin (minimum sound level, either Fast or Slow time weighted)
  • Ln (statistical parameters or "percentiles", such as LA10 and LA90)

Frequency Analysis for Tonal Noise

If environmental noise has a tonal content then it is sometimes necessary to measure it with 1/3 Octave Band Filters. The CEL633C1 meter includes this feature. For more information about the differences between the meters available please click the Which Meter? tab.

Construction and Demolition Site Noise

For medium term noise monitoring in and around sites during construction and demolition work. For longer term monitoring we recommend the EM2030 Environmental Noise Monitor. For monitoring over a few weeks or months the Outdoor Kit should be ideal. The kit can be set up at a suitable location and left to run for a week. At this point you can take it back to the office to download and recharge, or take a laptop out along with a recharged battery to swap (additional batteries are not included).

The noise measurements required on construction sites tend to include the periodic LAeq and LA90.

Boundary Noise Monitoring

For short term and mobile boundary noise monitoring, this application is very similar to Construction Noise (described above). Noise limits may be set by a local authority, demanding that noise levels be monitored 24 hours around a site, sometimes at multiple locations. The measurement of LAeq and LA90 is normally required.

Longer term monitoring at fixed locations can be achieved with the EM2030 Noise Monitoring.

Road Traffic, Transport and City Noise

The Outdoor Noise Kit can be easily relocated, making short term (up to one week) measurements at multiple locations much easier. Monitoring the noise at the roadside or by rail links or airports usually demands the measurement of the LAeq, LA90 and LA10, all of which are carried out simultaneously on the CEL633 range of meters.

The Sound Level Meters

The WPK-633 Outdoor Noise Kits can be supplied with any of the CEL63x range of sound level meter, from the lowest cost CEL632A2 to the top specification CEL633C1. The main decisions to make are:

  • Type 1 or Type 2 (Class 1 or Class 2)
  • Environmental noise parameters and timers?
  • Frequency analysis?

Our recommendation is to have either of the following.

CEL633A1 Sound Level Meter

  • A Type 1 Integrating sound level meter with additional environmental noise parameters, timers and data logging.
  • Outdoor Kit Order Code: WPK-633A1

CEL633C1 Sound Level Meter

  • Identical to the meter above but with real-time 1/3 octave band filters, for additional tonal noise analysis.
  • Outdoor Kit Order Code: WPK-633C1

Frequency Analysis

The "C" version of the meters have real-time Octave and 1/3 Octave Band Filters. These may be required for the analysis of tonal noise in some applications. This will be laid out in the regulations you are working to (if any exist). If you have any doubt then please contact us for advice.

If you are unsure then we can easily upgrade the CEL633A1 (without filters) to the CEL633C1 (with filters) without you having to return the equipment to us - we just send you a small program and access code to carry out the upgrade yourself.

Type 1 or Type 2

This defines the accuracy of the sound level meter in accordance with the ANSI S1.4 standard. Also referred to as "Class 1" or "Class 2" by the newer IEC 61672 standard. Although these standards are not identical, all the Type 1 meters mentioned here also meet IEC 61672 to Class 1. And the same for Type 2 / Class 2.

Many environmental noise regulations demand the use of a Type 1 / Class 1 integrating sound level meter. If your regulations or standards do not demand this then you can use Type 2, which costs a little less.

Our recommendation for environmental noise monitoring is to use Type 1. These microphones have a higher sensitivity and will measure lower sound levels, which can be important in quieter environments and at night.

Both of the meters that we recommend, the CEL633A1 and CEL633C1 are Type 1. Please contact us for a quotation for a Type 2 Outdoor Kit.

Environmental Noise Parameters and Timers

The lower cost CEL632 range of meters are very similar to the CEL633 range, but do not have the additional environmental noise parameters (such as LA10 and LA90), and do not have the advanced timers. For some applications this is not an issue, so the lower cost CEL632 might be suitable. If you are unsure then please contact us for advice as most environmental noise applications will require the additional features.

If you choose the CEL632 model then we can always upgrade it later to a CEL633 model.

Both of the meters that we recommend, the CEL633A1 and CEL633C1, include these environmental parameters and automatic timers. Please contact us if you need a quotation for a kit with the lower cost CEL632 range of meters.

Environmental Noise Measurements

Most environmental noise surveys require the following parameters, or a subset of these:

  • LAeq - The A-weighted average sound level
  • LAmax - The maximum A weighted sound level (Fast or Slow)
  • LA90 - The sound level exceeded for 90% of the time (background noise)
  • LA10 - The sound level exceeded for 10% of the time

The measurements will usually be carried out over 5, 15 or 60 minute periods, repeating throughout the survey period.

Some applications need measurements of these acoustic parameters over curfew periods, so for example between 11pm at night and 7am in the morning.

The meters we recommend for use with the Outdoor Kit include all these parameters, and many more.

Timers and Periodic Measurements

These meters have a selection of timer, periodic and cumulative modes that they can operate in. Here we just cover the most common settings that are needed for most environmental noise measurements. Please contact us for more details if you have a specialist application that needs something different.

In Periodic Mode, the meter can be set to make repeating measurements, each of a fixed length that can be set in minutes or hours. The most common is to set the meter to make 5 minute, 15 minute or 1 hour periodic measurements.

In Timers Mode you can set the meter to measurements at certain times of day and different days of the week

You can set the meter to make one or more runs on different days and at different times. In the example on the left the meter is set to make measurements on any day, but only between 08:00 in the morning and 17:00 in the afternoon.

This reduces the number of measurements to download and look through, just measuring at the times that are needed.

Noise Profile

As well as the periodic measurements described above, the meter can record the "Noise Profile". This is usually used to give a detailed graph of the sound level over time. For example, storing the noise profile every second is much faster than usually needed to meet any regulations, but the resulting graph can be very a very useful picture to describe the nature of the noise being measured.

Voice Notes and Audio Recording

Before starting a measurement you can record Voice Notes, which in some environments is easier than writing things down. These are stored on the meter and can be listened to after downloading the measurements.

The meter is also capable of recording the audio during measurement. These recordings can be threshold triggered based on the sound level, making it much easier to identify the cause of high noise levels when the monitor has been left unattended.

For more details about this feature please visit the Audio Recording page for the CEL633A1 sound level meter.

1/3 Octave Band Measurements

The meter in the WPK-633C1 kit also records the 1/3 Octave Band spectrum. As well as measuring the usual Leq and Lmax in each band, the CEL633C1 also measures the statistical parameters (such as LA90 and LA10) in each of the bands.


The WPK-633A1 and WPK-633C1 Outdoor Noise Kits include the Insight software, which provides the following features:

  • Downloads the noise measurements and audio recordings
  • Stores the measurements in an easily navigated database
  • Allocate measurements for easy management and reporting (by place of measurement or process being measured)
  • Generate and print reports
  • Export to spreadsheet, PDF, etc.

If you just want to extract the measurements to a spreadsheet to generate your own reports then you can use the very basic CasellaDrive software, which is perfect for that purpose and is free to download.

Downloading Measurements

The sound level meter connects to the computer's USB port using a standard cable (one is included in the kit). The software automatically detects new measurements and transfers them to the Downloaded folder. From here you can categorize them and move them to more logical folders.

Noise Measurement Analysis

The results can be viewed in a table or on a graph. They can be color coded to indicate high noise levels, making it easy to spot problems at a glance.

The Noise Profile graphs can also be color coded and annotated. Zones can be added to help with "what if" calculations.

Most graphs and tabular result views can be exported or copied for inclusion in your own reports generated in a spreadsheet or word processor program.

Generating Reports

Using the report wizard, you can create reports based on a person, place or process.

  • Report data from multiple meters
  • Report wizard helps generate reports
  • Store data in a simple tree structure
  • Drag and Drop to organize the measurements
  • Export reports to PDF, JPEG, CSV, etc.