Ultrasonic metering technology
The ultrasonic meter is without any movable parts. Two ultrasonic transducers are used to send sound signals both against and with the flow. The ultrasonic signal traveling with the flow reaches the opposite transducer first. The time difference between the two signals can be converted into flow velocity and subsequently into volume. This method has proven to be extremely measuring stable and endurable. Mechanical meters contain an impeller which is vulnerable to particles and chalk sediments. A possible consequence is that the meter will over time stop registering the very low flow rates that can be signs of leaks in the system.
Illustration 1: Sectioned ultrasonic meter showing the ultrasonic metering principle.
The ultrasonic metering method’s accuracy and measuring stability over time are being repeatedly confirmed by accredited international labs like the German energy efficiency association, AGFW, and random checks performed by Danish authorities3
Kamstrup’s ultrasonic meters are standardized according to the EU Metering Directive (MID) which is accepted as standard in 31 countries.
Thus experienced in ultrasonic metering technology it seemed only a natural extension of the product program when Kamstrup launched its first ultrasonic water meter in 2007. It was soon deployed in Greenland where more than 10,000 water meters were installed and integrated in a multi-utility system with electricity meters and heat meters.
While the metering principle has remained the same since the beginning in 1991 the measurement stability has been further improved and the power consumption reduced which has resulted in a battery lifetime of 16 years.
The ultrasonic measuring method provides an abundance of data material which is being processed in the calculator by means of micro processing technology and made available for analysis and network optimization.
Based on the first promising experiences with intelligent water metering, Kamstrup develops the MULTICAL 62 with extended communication options, improved battery lifetime and higher resolution. The higher resolution means that a residential water meter is now able to read liters down to 0.01 l., which is of great importance when the meter must be re-verified.