R137/2012-A-NL1-20.16 Rev. 4

OIML Member State The Netherlands

Number R137/2012-A-NL1-20.16 revision 4 Project number 3983639 Page 1 of 9

Issuing authority

NMi Certin B.V.

Person responsible: M.Ph.D. Schmidt

Applicant and Manufacturer

KROHNE Altometer Kerkeplaat 12 3313 LC Dordrecht The Netherlands

Identification of the certified type

An ultrasonic gas meter Type:

ALTOSONIC V12

ALTOSONIC V12 Check

ALTOSONIC V12D

ALTOSONIC V12D Check

ALTOSONIC V12E

ALTOSONIC V12E Check

Characteristics

See following page(s)

This OIML Certificate is issued under scheme A.

This Certificate attests the conformity of the above identified type (represented by the sample(s) identified in the OIML Type Evaluation Report) with the requirements of the following Recommendation of the International Organization of Legal Metrology (OIML):

R 137-1:2012 "Gas meters"

Accuracy class

0,5 or 1,0 (depending on meter type, piping configuration and flow disturbance, see tables 1, 2 and 3 on the next page for a detailed overview)

This Certificate relates only to the metrological and technical characteristics of the type of measuring instrument covered by the relevant OIML International Recommendation identified above. This Certificate does not bestow any form of legal international approval.

This certificate and supporting reports comply with the requirements of OIML-CS-PD-07 clause 6.2.

Important note: Apart from the mention of the Certificate's reference number and the name of the OIML Member State in which the Certificate was issued, partial quotation of the Certificate and of the associated OIML Type Evaluation Report(s) is not permitted, although either may be reproduced in full.

Issuing Authority

NMi Certin B.V., OIML Issuing Authority NL1 12 December 2025

Certification Board

This document is issued under the provision that no liability is accepted and that the applicant shall indemnify third-party liability.

The notification of NMi Certin B.V. as Issuing Authority can be verified at www.oiml.org

This document is digitally signed and sealed. The digital signature can be verified in the blue ribbon at the top of the electronic version of this certificate.

Number R137/2012-A-NL1-20.16 revision 4 Project number 3983639 Page 2 of 9

The conformity was established by the results of tests and examinations provided in the associated reports:

• CVN-710381-01 Rev. 1a dated 25 March 2009 that includes 45 pages;

• NMi-14200114-01 dated 29 October 2014 that includes 18 pages;

• NMi 1902254-01 dated 21 December 2018 that includes 33 pages;

• NMi-1901377-01 dated 8 October 2019 that includes 22 pages;

• NMi-2408281-01 dated 31 January 2020 that includes 17 pages;

• NMi-2533860-01 dated 24 December 2020 that includes 12 pages;

• NMi-3666357-01 dated 6 June 2025 that includes 33 pages;

• NMi-3983639-01 dated 12 December 2025 that includes 23 pages.

Characteristics of the measuring instrument

The general characteristics of the family of instruments are presented in table 1 (ALTOSONIC V12), table 2 (ALTOSONIC V12D), table 3 (ALTOSONIC V12E) and table 4 (all meter types). Table 5 presents the operating ranges per transducer type (all meter types). The flow characteristics are presented in table 6 (ALTOSONIC V12), table 7 (ALTOSONIC V12D), and table 8 (ALTOSONIC V12E).

All meter types, ALTOSONIC V12, ALTOSONIC V12D, and ALTOSONIC V12E can also be equipped with an additional non-metrological relevant index, meter types: ALTOSONIC V12 Check, ALTOSONIC V12D Check, and ALTOSONIC V12E Check.

The ALTOSONIC V12E has identical general specifications as the ALTOSONIC V12D. However, the ALTOSONIC V12E has an improved production design with a different inlet configuration and underwent additional testing to achieve a lower classification and higher Qmax speeds. For better differentiation compared to products already in use (on the market), the ALTOSONIC V12E has been introduced.

OIML Certificate

OIML Member State The Netherlands

Number R137/2012-A-NL1-20.16 revision 4

Project number 3983639

Page 3 of 9

Remarks regarding table 1, 2 and 3:

• xxD = Minimal length of straight inlet/outlet piping (where x can be 0...9).

• FC = Flow conditioner.

• USM = Ultrasonic gas meter.

Hereinafter:

• the ALTOSONIC V12 & ALTOSONIC V12 Check are also referred to as ALTOSONIC V12 (Check);

• the ALTOSONIC V12D & ALTOSONIC V12D Check are also referred to as ALTOSONIC V12D (Check);

• the ALTOSONIC V12E & ALTOSONIC V12E Check are also referred to as ALTOSONIC V12E (Check).

OIML Member State The Netherlands

Number R137/2012-A-NL1-20.16 revision 4 Project number 3983639

Page 4 of 9

Remarks regarding table 5:

[1] The maximum gas temperature also depends on the chosen $ Q_{\mathrm{min}} $ as specified in table 5 or 6. The resulting limiting value for $ T_{\mathrm{max}} $ is normative.

OIML Member State The Netherlands

Number R137/2012-A-NL1-20.16 revision 4

Project number 3983639

Page 5 of 9

Remarks regarding table 6:

[1] If higher values are chosen for $ Q_{\mathrm{min}} $ or $ Q_{t} $ and/or lower values for $ Q_{\mathrm{max}} $ , it has to be taken into account that:

• If ratio $ Q_{\mathrm{max}} / Q_{\mathrm{min}}\geq 5 0 $ then: $ Q_{\mathrm{max}} / Q_{t}\geq 1 0 $

• If ratio $ Q_{\mathrm{max}} / Q_{\mathrm{min}} \geq 5 $ and $ < 50 $ then: $ Q_{\mathrm{max}} / Q_{\mathrm{t}} \geq 5 $

[2] The maximum $ Q_{\mathrm{m a x}} $ depends on the transducer type and installation conditions (mild or severe flow disturbances).

[3] The maximum operating pressure （ $ p_{\mathrm{m a x}} $ ）depends on the installed transducer according to table 5.

[4] Regarding $ p_{\min} $ and $ p_{\max} $ see also the section "Installation conditions, working pressure" on page 8.

[5] Associated internal bore may differ for certain schedule sizes. In such cases the alternate flowrates are recalculated as follows:

$$ Q _ {2 =} \frac {D _ {2} ^ {2}}{D _ {1} ^ {2}} \cdot Q _ {1} = \left(\frac {D _ {2}}{D _ {1}}\right) ^ {2} \cdot Q _ {1} $$

$ \mathrm{D}_{1} $ : Associated internal bore dimension [mm] (above table)

$ \mathrm{D}_{2} $ : Alternate internal bore dimension [mm]

$ Q_{1} $ : Associated flowrate $ [\mathrm{m}^{3} / \mathrm{h}]$ (above table)

$ Q_{2} $ : Alternate internal bore flowrate $ [\mathrm{m}^{3}/\mathrm{h}] $

OIML Member State The Netherlands

Number R137/2012-A-NL1-20.16 revision 4

Project number 3983639

Page 6 of 9

Remarks regarding table 7:

[1] If higher values are chosen for $ Q_{\min} $ or $ Q_{t} $ and/or lower values for $ Q_{\max} $ it has to be taken into account that:

• If ratio $ Q_{\mathrm{max}} / Q_{\mathrm{min}} \geq 50 $ then: $ Q_{\mathrm{max}} / Q_{\mathrm{t}} \geq 10 $

If ratio $ Q_{\mathrm{max}} / Q_{\mathrm{min}} \geq 5 $ and $ < 50 $ then: $ Q_{\mathrm{max}} / Q_{\mathrm{t}} \geq 5 $

[2] The maximum $ Q_{\mathrm{m a x}} $ depends on the transducer type and installation conditions (mild or severe flow disturbances).

[3] The maximum operating pressure $ p_{\mathrm{max}} $ depends on the installed transducer according to table 5.

[4] Regarding $ p_{\min} $ and $ p_{\max} $ see also the section "Installation conditions, working pressure" on page 8.

[5] Associated internal bore may differ for certain schedule sizes. In such cases the alternate flowrates are recalculated as follows:

$$ Q _ {2 =} \frac {D _ {2} ^ {2}}{D _ {1} ^ {2}} \cdot Q _ {1} = \left(\frac {D _ {2}}{D _ {1}}\right) ^ {2} \cdot Q _ {1} $$

$ \mathrm{D}_{1} $ : Associated internal bore dimension [mm] (above table)

$ \mathrm{D}_{2} $ : Alternate internal bore dimension [mm]

$ Q_{1} $ : Associated flowrate $ [\mathrm{m}^{3} / \mathrm{h}]$ (above table)

$ Q_{2} $ : Alternate internal bore flowrate $ [\mathrm{m}^{3}/\mathrm{h}] $

OIML Member State The Netherlands

Number R137/2012-A-NL1-20.16 revision 4 Project number 3983639

Page 7 of 9

Remarks regarding table 8:

[1] If higher values are chosen for $ Q_{\mathrm{min}} $ or $ Q_{t} $ and/or lower values for $ Q_{\mathrm{max}} $ , it has to be taken into account that:

$$

• \quad \text {I f r a t i o} Q _ {\max } / Q _ {\min } \geq 5 0 \quad \text {t h e n}: Q _ {\max } / Q _ {\mathrm {t}} \geq 1 0 $$

$$

• \quad \mathrm {I f r a t i o} Q _ {\max } / Q _ {\min } \geq 5 \mathrm {a n d} < 5 0 \quad \mathrm {t h e n :} Q _ {\max } / Q _ {\mathrm {t}} \geq 5 $$

[2] The maximum $ Q_{\mathrm{m a x}} $ depends on the transducer type and installation conditions (mild or severe flow disturbances).

[3] The maximum operating pressure （ $ p_{\mathrm{m a x}} $ ）depends on the installed transducer according to table 5.

[4] Regarding $ p_{\min} $ and $ p_{\max} $ see also the section "Installation conditions, working pressure" on page 8.

[5] Associated internal bore may differ for certain schedule sizes. In such cases the alternate flowrates are recalculated as follows:

$$ Q _ {2 =} \frac {D _ {2} ^ {2}}{D _ {1} ^ {2}} \cdot Q _ {1} = \left(\frac {D _ {2}}{D _ {1}}\right) ^ {2} \cdot Q _ {1} $$

$ \mathrm{D}_{1} $ : Associated internal bore dimension [mm] (above table)

$ \mathrm{D}_{2} $ : Alternate internal bore dimension [mm]

$ Q_{1} $ : Associated flowrate $ [\mathrm{m}^{3} / \mathrm{h}]$ (above table)

$ \mathrm{Q}_{2} $ : Alternate internal bore flowrate $ [\mathrm{m}^{3}/\mathrm{h}] $

OIML Member State The Netherlands

Number R137/2012-A-NL1-20.16 revision 4 Project number 3983639 Page 8 of 9

Installation conditions:

Installation requirements

Any components which could affect the gas flow must be avoided within the prescribed inlet pipe length. The inlet pipe must be designed as a straight pipe section of the same nominal diameter as the gas meter. The necessary straight pipe length is stated on the name plate of the meter.

The installation requirements, based on accuracy class and mild and/or severe flow disturbance are specified in table 1, 2 and 3. The used flow conditioner (if applicable) is of type: "KROHNE flow conditioner" or "FC3".

Working pressure

The spool piece and the transducers can be used up to the specified pressure in table 5 ( $ p_{\mathrm{m a x}} $ depending on transducer type).

The two pressures, at which the meter shall be calibrated, without intermediate adjustment over its full flow rate range during initial verification （ $ p_{\mathrm{min}} $ calibration and $ p_{\mathrm{max}} $ calibration），shall be equal to the operating pressure range （ $ p_{\mathrm{min}} $ and $ p_{\mathrm{max}} $ ）as given on the type plate.

In case the claimed type plate values $ ( p_{\mathrm{max}}-p_{\mathrm{min}}) < = $ （ 50- $ p_{\mathrm{min}} $ table 6,7,8), only 1 calibration pressure $ ( p_{\mathrm{calibration}}) $ is necessary.

For a maximum working pressure $ \left(p_{\mathrm{m a x}}\right) $ of the ultrasonic gas meter above 60 bar(a), a maximum calibration pressure $ \left(p_{\mathrm{m a x}}\right) $ calibration) of around 60 bar(a) is allowed since this is the highest possible test pressure at any test location traceable to (inter)national standards.

Meter in series

It is allowed to install the ALTOSONIC V12 (Check), ALTOSONIC V12D (Check) and ALTOSONIC V12E (Check) meters in series with another ultrasonic meter by directly connecting the outlet of the first meter to the inlet of the second meter, while applying the following conditions:

• Both meters are calibrated at the same time, being mounted together;

• The installation conditions of both meter types are fulfilled.

Reduced bore

In case the ALTOSONIC V12 (Check), ALTOSONIC V12D (Check) or ALTOSONIC V12E (Check) is applied in series with a reduced bore meter, the following condition is also applicable:

• If the ALTOSONIC V12 (Check), ALTOSONIC V12D (Check) or ALTOSONIC V12E (Check) is mounted on the second position, then the angle of inclination of the reduced bore shall be less than $ 7^{\circ} $

Non-essential parts:

Krohne Care-Board (optional)

A board with additional IO and a diagnostic expert system to interpret standard diagnostic parameters that provides also long term trending. It is allowed to add the Care-Board to existing meter electronics which were originally setup without a Care-Board.

OIML Certificate

OIML Member State The Netherlands

Number R137/2012-A-NL1-20.16 revision 4 Project number 3983639

Page 9 of 9

Certificate history:

This revision replaces the previous versions.