A consumption meter is provided for measuring one of a fluid flow rate and an energy flow rate of a utility, the consumption meter comprising: measuring means for measuring the one of the fluid flow rate and the energy flow rate of the utility, an electronic circuit for operating the measuring means, a power source for operating the consumption meter and having a power source energy, and a power source energy calculation unit being arranged to (a1) calculate an estimate of the remaining power source energy, (a2) calculate a budgeted remaining power source energy, and (a3) compare the estimate of the remaining power source energy and the budgeted remaining power source energy, and, wherein the consumption meter is arranged to (b1) measure the one of the fluid flow rate and the energy flow rate with a measurement frequency F1; (b2) measure the one of the fluid flow rate and the energy flow rate with a measurement frequency F2, F2 > F1, provided that a first change in any of the fluid flow rate or the energy flow rate exceeds a first predetermined change of the fluid flow rate or the energy flow rate, respectively, and that the estimate of the remaining power source energy exceeds the budgeted remaining power source energy, and (b3) measure the one of the fluid flow rate and the energy flow rate with the measurement frequency F1, provided that a second change in any of the fluid flow rate or the energy flow rate goes under a second predetermined change of the fluid flow rate or the energy flow rate, respectively, or that a certain time interval has elapsed during (b2).
The consumption meter provided is capable of measuring precisely the fluid flow rate or the energy flow rate during periods of changes with such flow rates without compromising the consumption of power source energy of the consumption meter.