If you have recently acquired a Type 2250 or Type 2270 sound level meter and need to get up and running quickly, we have made this article for you. Detailed steps to getting up and running are in the manual of course, but here we present essential tasks and features to start using your sound level meter.
Table of contents:
- Calibrating your sound level meter
- SD cards for Type 2250 & Type 2270
- Choosing a measurement template
- How to apply A or C filters – frequency weighting
- How to measure 1/1- or 1/3-octaves
- How to use voice notes
- How to write a note
- Removing disturbances during the measurement
- Monitoring the measurement state of the sound level meter
- How to upload data to your PC
To calibrate your sound level meter, use Sound Calibrator Type 4231. It provides a stable sound pressure at 1 kHz and has minimal susceptibility to environmental factors. The procedure itself is relatively simple, and on the sound level meter the procedure is referred to as Standard Calibration.
To perform acoustic calibration and to fit the calibrator:
- Stand away from loud sound sources that may interfere with the calibrator’s signal.
- Switch on the sound level meter.
- Tap Calibration to open the Calibration screen.
- Following the first part of the instruction in the Status Field, fit Sound Calibrator Type 4231 carefully onto the microphone of the sound level meter.
- Switch on the calibrator.
- Wait a few seconds for the level to stabilize and start the calibration
While the sound level meter is searching for the calibration signal and the signal level is stabilizing, the ‘traffic light’ LEDs indicate a short green flash every second. When the level is stable, the traffic light indicates a steady green and the signal is measured and used for calibration.
Once the calibration has been completed successfully, the traffic light indicates a short yellow flash every 5 seconds. The sensitivity is automatically calculated and displayed in a pop-up together with the deviation from the last calibration. Tap Yes to accept and use the new sensitivity and save it in the calibration history. Tap No to disregard the new calibration and continue with the old calibration.
If the calibration deviates more than ±1.5 dB from the initial calibration (microphones only), then the calibration is stopped without changing the calibration of the sound level meter. The traffic light will indicate a fast flashing red and an error description will appear in the status field.
Type 2250 and Type 2270 only support industrial quality SD cards with up to 8 GB of storage space. We recommend Brüel & Kjær item number UL-1017, which is approved for use with Type 2250/2270. To use an SD card:
- Insert the SD card into one of the slots at the bottom of Type 2250 or Type 2270.
- If the SD card has not been used before, the system will perform a speed test to ensure the card is fast enough.
- If the card is accepted, the sound level meter will prompt if you want to use it for storing new measurements.
- You can see where measurements are being stored on the second line of the display.
- Sound Level Meter: This template comes as standard on Brüel & Kjær’s sound level meters. Use this for simple cases, where all you need are overall broadband numbers like Leq, Lmax, Lmin or statistics.
- Frequency Analyzer: This template comes as standard on Type 2250 and Type 2270. Use this for simple cases, where you need to know the frequency content of sound, but still only need overall numbers over time. It can be used to identify sounds by frequency and/or assess if noise is ‘tonal’ and, therefore more annoying.
- Logging and Enhanced Logging: Use these templates when you need to know how the level changes over time. They are also useful when there are many sources to separate. Logging gives the maximum amount of flexibility in post-processing. Note this licence is optional and needs to be ordered separately.
Templates are customizable, and it is possible to change settings in a template and/or make copies. Make a template for each job, and name them after that job.
- Tap the menu button in the bottom-left corner.
- Select Setup.
- Expand Frequency Weightings.
From here, you can select 2 broadband weightings (rms) and one broadband peak weighting. Depending on your template, you can also choose a weighting for spectra.
- Tap the menu button in the bottom-left corner.
- Select Setup.
- Expand Frequency Settings.
- Choose your preferred Bandwidth: 1/1-octave or 1/3-octave.
How to use voice notes
Voice notes and written notes can add valuable information to your measurements. Voice notes are not captured through the main microphone, but through a small microphone at the rear of the sound level meter.
Here’s how to apply voice notes:
- Before, during* or after your recording, press and hold the top-right physical button on your sound level meter to begin a recording.
- Speak into the microphone at the rear of the sound level meter.
- Release the button when you are done recording.
* For Logging Software BZ-7224 and Enhanced Logging Software BZ-7225, annotations can be added directly to the measurement profile during the measurement.
- Before, during or after your measurement go to the menu and select Add Note to Current Measurement.
- A blank notes screen will appear, where you can make written comments about the measurement, using the standard full character keyboard that appears at the bottom of the screen.
Removing disturbances during the measurement
You can use the ’back-erase‘ button on your sound level meter to remove disturbances from your measurements. This can be very helpful if something disturbs you in the middle of a measurement.
For the Sound Level Meter and Frequency Analyzer templates do as follows:
- Press ‘back-erase’ when the disturbance occurs. The last 5seconds will be erased from measurement and the sound level meter will pause.
- Press ‘start/pause’ to continue measurement when the disturbance ends.
In the Logging and Enhanced Logging templates do as follows:
- Press ‘back-erase’ when the disturbance occurs. An ‘exclude’ marker (above the profile) will be started on the measurement.
- Press ‘back-erase’ again when the disturbance ends. The ‘exclude’ marker will stop at this point.
- Download the measurement into Measurement Partner Suite.
- Adjust the start and end times of the exclude marker to capture the entire disturbance.
- Open the Marker table.
- Read the values from the ‘Total-exclude’ row to get levels for the measurement minus the exclude periods.
Info on back-erase is in section 4.5.3 of the user manual. https://bksv.com/downloads/2250/be1713.pdf
Monitoring the measurement state of the sound level meter
Type 2250 and Type 2270 sound level meters have coloured LEDs at either side of the ’start/pause’ button . Often referred to as the ‘traffic lights’, this feature helps you understand the state of your device. The colour of the light lets you know what’s going on, even at a distance, so you don’t need to stand right next to your device and watch the screen during the measurement. The sound level meter emits these different lights depending on it’s state:
- Green light – currently recording/measuring
- Flashing yellow light – ready to measure, paused, and not currently recording/measuring
- Red light – something is wrong, check the device
How to upload data to your PC
After your measurement is finished you will want to upload your measurement data to your PC. Keeping track of your projects quickly becomes a central job and here our software can help.
Be sure that you have installed Measurement Partner Suite (MPS) BZ-5503 on your PC and it is running before connecting any sound level meter or SD card. You will have received Measurement Partner Suite with your sound level meter and will be kept up-to-date when a new version is ready for download. The latest version is always available online.. You can now transfer data either via a USB cable attached to Type 2250/2270 or via the SD card:
- Connect either the sound level meter via USB cable to your PC or use an SD card reader.
- In MPS, the sound level meter will become visible as a removable disk. Here you can simply select the sound level meter and browse your files.
- To move files from your sound level meter to your PC, drag and drop them within MPS into your project archive.
- If there is no suitable archive, you can create new archives on your local hard drive, network drive, etc.
You are now ready to start recording, measure, analyse and create reports with your Type 2250 or Type 2270. If you need any more information about how to use the sound level meter, check out the user manual (provided with the sound level meter or available online) – or give us a call.