Definition: A Type Approved Sound Level Meter is a noise measuring instrument that has been tested and verified as meeting a standard, such as IEC 61672-2, by a recognised testing laboratory, such as the PTB in Germany, the LNE in France or Applus+ in Spain.
Explanation: A good quality sound level meter from a reputable manufacturer will have been designed to meet a standard such as IEC 61672-1:2002.
Manufacturers can state that an instrument meets the standard and in many situations this is acceptable. However, there are circumstances where an independent verification of these claims is required. A Type or Pattern Approval certificate from a recognised test laboratory will give this.
Testing an instrument for Type Approval.
The IEC 61672 standard for sound level meters is split into three parts.
The first, part 1, lays down the criteria for the sound level meter in terms of acoustic measurements, electromagnetic and environmental performance. It also details the information that must be available for the instrument. This typically includes information about the effect of the instruments case on measurements and any corrections needed to test the instrument.
Part 2 of IEC 61672 defines a set of tests that should be carried out to verify that the instrument does indeed meet Part 1 of IEC 61672. These tests cover a wide range of different technical aspects of the instrument.
Part 3 of IEC 61672 specifies tests that should be carried out when the instrument is calibrated. This is known as periodic verification.
Typically, a test laboratory would test a sample set of the instruments to ensure that each one meets the required performance. Once these tests have been completed and if the instrument has passed, it will be granted a Type Approval or Pattern Approval certificate.
It is common for the certificate to state the version of the instrument and any version of internal software that the instrument had when it was tested along with any accessories that the instrument must be used with for the Type Approval to be valid.
This is to ensure that if the manufacturer updates the internal software in the instrument, the certificate of approval is no longer valid and the instrument would have to be re-tested.
If you are purchasing a sound level meter and type approval is important, check that the instrument that you are buying has a valid certificate and that the software in the instrument meets that detailed on the test certificate.
The following Cirrus Optimus Red & Green Sound Level Meters have Type Approval:
Class 1 Optimus Red Sound Level Meters with Type Approval
- CR:161AÂ Class 1 Integrating Sound Level Meter – Type Approval from PTB, LNE & Applus+
- CR:161BÂ Class 1 Integrating Sound Level Meter with data logging – Type Approval fromÂ PTB, LNE & Applus+
- CR:161CÂ Class 1 Integrating Sound Level Meter with 1:1 octave band filters & data loggingÂ Â – Type Approval fromÂ PTB, LNE & Applus+
Class 1 Optimus Green Sound Level Meters with Type Approval
- CR:1710Â Class 1 Data Logging Sound Level MeterÂ – Type Approval from PTB, LNE & Applus+
- CR:171AÂ Class 1 Data Logging Sound Level Meter with 1:1 Octave Band FiltersÂ – Type Approval from PTB, LNE & Applus+
- CR:171BÂ Class 1 Data Logging Sound Level Meter with 1:1 & 1:3 Octave Band FiltersÂ – Type Approval from PTB, LNE & Applus+
- CR:171CÂ Class 1 Data Logging Sound Level Meter with 1:1 & 1:3 Octave Band Filters & Tonal Noise DetectionÂ – Type Approval from PTB
All of these instruments are approved for use as handheld sound level meters with the microphone and preamplifier attached to the body of the instrument.
For more information about our range of Type Approved Sound Level Meters, please contact your Cirrus Office or local distributor.
Here are links to some other posts covering Type Approval for Sound Level Meters:
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