R137/2012-A-NL1-23.04 Rev. 2

OIML Member State The Netherlands

Number R137/2012-A-NL1-23.04 revision 2 Project number 3812256 Page 1 of 5

Issuing authority

Applicant and Manufacturer

NMi Certin B.V.

Person responsible: M.Ph.D. Schmidt

RMG Messtechnik GmbH Otto-Hahn-Strasse 5 35510 Butzbach Germany

Identification of the certified type

An ultrasonic gas meter Manufacturers mark: Type:

RMG Messtechnik GmbH USM-GT400

Characteristics

See following pages

This OIML Certificate is issued under scheme A.

This Certificate attests the conformity of the above identified type (represented by the samples 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

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.

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 Reports is not permitted, although either may be reproduced in full.

Issuing Authority

NMi Certin B.V., OIML Issuing Authority NL1 10 October 2024

Certification Board

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

Number R137/2012-A-NL1-23.04 revision 2 Project number 3812256 Page 2 of 5

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

• No. NMi-3498274-01 dated 19 May 2023 that includes 51 pages.

• No. NMi-3498274-01 revision 1 dated 22 May 2023 that includes 51 pages.

• No. NMi-3711995-01 dated 5 January 2024 that includes 23 pages.

• No. NMi-3812256-01 dated 10 October 2024 that includes 13 pages.

Characteristics of the measuring instrument

In Table 1 the general characteristics of the measuring instrument are presented. In Table 2 & 3 the characteristics of the family of instruments are presented.

OIML Member State The Netherlands

Number R137/2012-A-NL1-23.04 revision 2 Project number 3812256 Page 3 of 5

Table 2 Meter type, path configuration & installation conditions

The meter consists of a cylindrical spool piece with 6 horizontal direct paths, 2 paths on each level evenly distributed. See configuration below that can be combined in a single housing according to the table below.

[1] xD = Minimum straight inlet & outlet piping length

[2] FC = Flow conditioner: CPA55E

USM = Ultrasonic gas meter

[3] FC = Flow conditioner: LP35

[4] A temperature sensor can optionally be placed at least 1,5D downstream of the USM outlet.

[5] where the FC is always installed a fixed 5D (in case of CPA55E) or 10D (in case on LP35) from the USM.

The GT-400 meter is available in two variants reduced bore and full-bore variant.

The version with reduced bore can have a tapering with a chamfer of 7 degree to adjust the diameter of the connecting flanges to the diameter of the in- and outlet pipes.

OIML Member State The Netherlands

Number R137/2012-A-NL1-23.04 revision 2

Project number 3812256

Page 4 of 5

Remarks regarding table 3

[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 _ {t} \geq 1 0 $$

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

[2] Depending on the internal bore, the flow rate in $ m^{3}/h $ can be calculated.

The corresponding flow rates can be calculated as follows:

$$ Q = v \cdot \frac {1}{4} \cdot \pi \cdot D ^ {2} $$

Where:

Q = flow rate [m $ ^{3} / \mathrm{h} ]$

v = velocity [m/s]

D = internal diameter [m]

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 a nominal diameter <3% difference compared to the gas meter.

The installation requirements, based on accuracy class and mild and/or severe flow disturbance are specified in table 2. The used flow conditioner is of type: CPA55E or LP35.

Working pressure

The spool piece and the transducers can be used up to the specified pressure as given in table 1.

The following working pressure ranges are applicable:

• For a working pressure range $ \left(p_{\mathrm{min}}\right) \geq1 0 $ bar(g) a calibration on one pressure is sufficient. The working pressure range $ \left(p_{\mathrm{min}}\right) $ and $ p_{\mathrm{max}} $ ) as given on the name plate is allowed to be within $ \frac{1}{2}\cdot p_{\mathrm{fix}} $ and $ 2\cdot p_{\mathrm{fix}}. $

n

• For a working pressure range （ $ p_{\mathrm{min}} $ ）<10 bar(g) a calibration shall be performed on the two pressures at $ p_{\mathrm{min}} $ and $ p_{\mathrm{max}} $ as given on the name plate.

OIML Certificate

OIML Member State The Netherlands

Number R137/2012-A-NL1-23.04 revision 2 Project number 3812256 Page 5 of 5

The ultrasonic gas meter does not make use of an internal pressure or temperature sensor. The correct fixed density $ \left( \rho_{\mathrm{f i x}} \right) $ and fixed pressure setting $ \left( p_{\mathrm{f i x}} \right) $ shall be applied before calibration in the USM setting.

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

Thermowell

A thermowell may be mounted at $ \geq1,5\mathrm{D} $ and $ \leq5\mathrm{D} $ from the outlet of the meter in unidirectional flow measurement.

Alternative welded configuration of the gas meter

The central meter body can be welded directly onto the flanges or to inlet and outlet pipes. The welding may not cause more than a 3% diameter step. The meter shall be installed as stated in "Installation requirements". The central meter body, including welded piping or welded flanges, shall be calibrated as a meter package during the examination for putting into use of the gas meter.

Maintenance

A transducer path pair or a single transducer on a path can be exchanged without deterioration of the metrological performance.

Certificate history: