Offering you the right measuring, is our priority.

Metrology Metrology

Legal metrology is the science of measurement. It is very important for trade and our everyday lives. No market can function without correct measuring and without common units of measurement.

European Commission Website, 09.09.2021


 Illustration of legal metrology and its benefits
Our mission

No matter where you are in the world – our international metrology team will help you with any questions or requests about legal metrology, metrological services for sales and after sales (e.g. calibration tests, acceptance tests, inspections tests). We will be happy to assist you.

Our competence

Diehl Metering operates test laboratories at many locations in different countries, covering all common test technologies. Our testbench construction department develops and manufactures its own test facilities. However, we also use the expertise of established test bench builders.

Photo of a test laboratory
Our measuring instrument
Our traceability

Our measuring equipment is reliable and traceable to national and international standards. Our measuring instrument managers have the competence to determine uncertainties, to do internal calibrations and to select the best calibration laboratories for external calibration services.

We manage regular inter-laboratory loop comparisons between our DIEHL Metering laboratories and external laboratories.

Our wide range

Measured Variable Technology standard Temperature range Flow range
Volume of water Balance(s) 0,1 °C – 90 °C 0,006 m³/ h – 1.600 m³/h
  Piston 0,1 °C – 50 °C 0,001 m³/h - 10 m³/h
  Combined balance / piston 0,1 °C – 50 °C 0,001 m³/h - 25 m³/h
  Combined balance / mag meter 0,1 °C – 50 °C 0,010 m³/h - 1200 m³/h
Temperature sensor Bath 0 °C – 150 °C -
Energy calculator High precision resistances 2 K - 195 K -

Number of Testbenches: 61 / Test Equipment: 20 (as of 2022)
Our test equipment is traceable to national standards.

Our test equipment complies with international and national regulations (areas of validity according to the corresponding recognition certificates).


Regulation Site
European Measurement Equipment Directive Modul D Ansbach, Apolda, Bazanowice, Jinan, Saint-Louis
ISO 17025 Ansbach, Saint-Louis
Calibration Laboratory  
National state accredited laboratory Ansbach, Apolda, Vienna, Saint-Louis

Our Locations

Our laboratories are recognized in many countries and we have good contacts to other laboratories all over the world.
Our associations and alliances managers know the world of legal metrology and the key players in this domain.

Get in contact with our sales representant for inquiries.

Ansbach/Apolda Ansbach/Apolda

State-approved test centre

Our independent state authorized laboratories exercise public functions under the supervision of the state metrology authority.
The usage of utility meters in the field is defined by national regulations. You can find some further information for Germany here:

Faltblatt Elektrizität Gas Wasser Wärme
Infoblatt Eichfristen
Infoblatt Kennzeichnung
Infoblatt Neues Eichrecht Verwender

We can proof our competence and our calibration laboratory is accredited according ISO 17025.

ISO 17025 calibration laboratory

Factory test centre

We provide independent metrology inspections for our DIEHL products. Field returns pass our laboratory for metrological analysis.

Re-verification by sampling water meter

Antrag auf Stichprobenprüfung

Legal meter evaluation water meter

Antrag auf Befundprüfung eines Wasserzählers
Ausbauprotokoll Wasserzahler

Legal meter evaluation thermal energy meter

Antrag auf Befundprüfung eines Wärmezähler
Antrag auf Befundprüfung eines Wärmezähler Teilgeräte
Ausbauprotokoll Wärmezähler

Unit rates

For official examination water meter
Gebührensatz Befundprüfung Wasserzähler

For official examination thermal energy meter
Gebührensatz Befundprüfung Wärme-/Kältezähler

For calibration fees and conformity assessment
Gebührensatz Eichgebühren/Konformitäsentgelte/Werks-Prüfkosten

As a subject of corporate metrology, we are providing all required legal metrology activities connect with produced artides.
Our equipment and testing mesures are under regular control of national and international certification bodies.
Efforts for accreditation related to ISO 17025:2017 (initiated in 2021) will allow our internal laboratory to provide the highest services for internal and external customers.

As a subject of corporate metrology, we are providing all required legal metrology activities connect with produced articles.
Our equipment and testing measures are under regular control of national and international certification bodies.

Our Calibration laboratory is accredited according to NF EN ISO/IEC 17025 : 2017

Main documents linked to this activity:

  • 17025 certificate with technical annex (see link to global and to Cofrac site)

National specificities:

Diehl Metering Saint-Louis is certified for Thermal Energy Meters Installations according to:

  • Décret 2001-387 from 3rd May 2001 and decision from 21st December 2018
    Arrêté du 3 septembre 2010

Mains documents linked to this activity:

  • Identification mark SL68
  • Newsletter "Verification of Thermal energy installations"

Calibration obligation for water meters, heat meters and cooling meters

Cold and hot water meters as well as heat meters and cooling meters and their sub-assemblies that are used in the course of business or are kept ready for use without special preparation must be calibrated/ conformity assessed.

Calibration / Conformity assessment

The water, heat and cooling meters are calibrated by the calibration authority or by authorized calibration laboratories.

Marking during calibration / conformity assessment

The water, heat and cooling meters are marked as calibrated by the calibration authority or the authorized calibration bodies by means of the main stamp or are conformity assessed in accordance with the recognized quality management system of the European MID Directive 2014/32/EU.

Prerequisites for verification/conformity assessment - Verifiability of measuring instruments

Measuring instruments that are to be calibrated must be of a type that has been approved for calibration. The characteristic of the type approval is the approval mark affixed to the measuring instrument, e.g. national approval, EEC approval or EC type examination certificate with registered marks and numbers.

Calibration period

The calibration/conformity assessment is not valid indefinitely. For cold and hot water meters, heat and cooling meters, the validity period is 5 years.


Cold and hot water meters, heat and cold meters: calibration period 5 years

Calibration 2017 - expiry of calibration 31.12.2022

This means that the water and heat meters must be recalibrated or replaced by validly calibrated meters by the end of these periods at the latest. There is no separate request for this. Utility companies have the option of extending the calibration validity by three or five years by means of a sampling procedure. 

The validity expires prematurely if, among other things, the meter does not comply with the traffic error limits after calibration, e.g. due to the water quality, or if the main stamp or a security stamp has been damaged.