Vehicle Noise Test Solution

Noise Level Measurement Solutions for Vehicle Noise

The XL2 Sound Level Meter provides the dedicated solution for vehicle noise monitoring of cars and motorcycles at the roadside. All measurement data is stored on the SD card. Simultaneously the XL2 may record a wav-file for documentation. The event recorder functionality triggers the measurement by programmable level thresholds.

At a Glance

  • Exhaust noise level
  • ISO 5130, EU directive 70/157/EEC and ยง29 StVZO
  • Annual inspection and survey of road vehicles

XL2 Measurement Functions

XL2 with M4260 Measurement Microphone

Noise Level SPL

Measuring the following parameters:
  • LAFmax
    (maximum noise level with A-weighting)
  • LAeq
    (averaged noise level for environmental noise verification)

How to measure?

  • The environmental noise LAeq shall be at least 10 dB below the measured A-weighted exhaust noise level.
  • Position the measurement microphone directed towards the exhaust pipe at a distance of 0.5 m at a 45° angle in the same height; the height shall be minimum 0.2 m above ground.
  • Connect the XL2 Analyzer with the 5 m ASD cable to the measurement microphone.
  • Start the XL2 with the measurement profile ISO 5130.
  • Increase the engine speed gradually from idle to the measurement rpm according the table below.
  • Start the measurement.
  • Hold the measurement rpm for one second and release the throttle control rapidly, thus the engine speed returns to idle.
  • The measurement stops automatically after the entire deceleration period.
  • Repeat the measurement until LAFmax is within 2 dB for three consecutive measurements.
  • The final result LAFmax is calculated as average of these 3 measurement results.


Rated engine speed Measurement rpm Application
< 5000 rpm 75% of rated rpm road vehicles having at
least four wheels
5000 - 7500 rpm 3750 rpm any road vehicles
> 7500 rpm 50% of rated rpm any road vehicles


Type Approval Option

The Type Approval Option, when installed on your XL2, upgrades the instrument to the XL2-TA, the sound level meter for certified measurements. The XL2-TA, together with the M2230 microphone and Shroud jacket, forms a type-approved sound level meter offering class 1 performance in accordance with IEC 61672:2014, IEC 61260:2014, ANSI S1.4:2014 and ANSI S1.11:2014 standard.

Type approved sound level meter configuration:
  • XL2-TA Sound Level Meter (XL2 with Type Approval Option installed)
    • Firmware V3.11
    • Optional: Extended Acoustic Pack Option
    • Optional: XL2 Input Keypad
  • M2230 Measurement Microphone
  • Shroud MXA01

XL2-TA Type Approval Certificate


Exel Set for Noise Measurements

Exel Kit for Vehicle Noise Inspection

  • XL2 Sound Level Meter
  • M2230 Measurement Microphone
  • ASD Cable for XL2
  • Measurement Tape
  • Tripod as Microphone Stand
  • Mains Power Adapter
  • Exel System Case

Get more Information