Highest measurement accuracy. Maximum reliability.

After 4,800 hours of intensive endurance testing, our heat meters have once again confirmed their exceptional measurement accuracy – and secured the top rating from AGFW, the German Energy Efficiency Association for Heating, Cooling and Combined Heat & Power (CHP) supply.

For Kamstrup, quality is not a minimum standard but an investment in the future. That is why the company develops heat meters that provide long-term value to its customers and clearly exceed the legal EN 1434 requirements. This philosophy pays off: in the current AGFW heat meter test program (WZP VIII-1), the measuring performance of the devices again received the highest grade. 

Focus of the test

The central component of the test was the flow sensor, one of the three key subassemblies of a heat meter. The tested sensors of the compact MULTICAL® 403 meter in sizes qp 0.6, 1.5, 2.5 and 3.5 m³/h were obtained by AGFW through various utility companies. The result impressively confirms that Kamstrup continues to set standards in precision and reliability.

The AGFW test at a glance

The AGFW heat meter test program (WZP) provides solid insights into the measurement accuracy, durability, and maintainability of both market-available and new flow sensors. On the modern test bench, small sensors with nominal flow rates from qp 0.6 to 3.5 m³/h are subjected to extensive tests and an intensive long-term stress program.

In the 2024/2025 period, heat meters from different manufacturers were examined within WZP VIII-1. First, they check the measuring accuracy of the devices – i.e., their precision compared with a reference measurement at test water temperatures of 50 °C and 75 °C.

The durability test shows whether a meter continues to measure reliably even after prolonged operation under wear conditions. The test program simulates the aging process through accelerated stress tests: over 4,800 hours, the sensors are exposed to 90 °C hot water – a procedure that goes well beyond the requirements of EN 1434.

Finally, the program also evaluates the maintainability of the devices – i.e., the ability to restore a flow sensor to a nearly-new condition through targeted measures such as cleaning or replacement of individual components. This is crucial for long service life and sustainable operation.

Quality qualifies

The outstanding durability of the MULTICAL® 403 was confirmed not only in WZP VIII-1, but also in a multi-year field trial in Germany, which was initiated as part of the “VDE FNN guideline on qualification procedures for sample testing of electronic electricity, gas, water, heat, and cooling meters” on November 19, 2019, and successfully completed at the end of 2024.  

This allows the calibration period in Germany to be extended by up to six years using the sample testing procedure. This is a clear advantage compared to the 2 years’ operation of meters without a passed qualification procedure or the previously common replacement of the meter at the end of the calibration period.  

This procedure represents a significant step towards more sustainable and efficient heat metering. Longer service lives reduce both financial and time expenditures for scheduled replacements. At the same time, the extended service lives contribute to sustainability.

In the name of quality

Since the introduction of the first thermal energy meter in the 1950s, uncompromising product quality has been Kamstrup’s top priority. Every meter goes through a strict quality assurance process to ensure maximum precision and reliability throughout its entire lifespan. The quality of a measuring device influences every step – from supplier selection to its very last day in use.

Learn more

Since all flow sensors of Kamstrup’s heat and cooling meters are based on a common platform, the excellent test results of the MULTICAL® 403 can be directly applied to other models as well, including the compact MULTICAL® 303 and the separate ULTRAFLOW® 54 flow sensor, which is used in combination with the MULTICAL® 603 and MULTICAL® 803 meters.