| 摘要 |
There is provided a method of determining the predicted usage of gas from a gas cylinder and valve assembly having a fixed internal volume. The method comprises determining, using a sensor assembly, the mass of gas in the gas cylinder at a time t, determining, at time t, the average flow rate of gas from the gas cylinder; and determining, at time t, the time remaining until the quantity of gas in the gas cylinder reaches a predetermined level, the time remaining being determined from the mass of gas in the gas cylinder at time t, the average flow rate of gas from the gas cylinder at time t, and a predetermined scaling factor selected in dependence upon the proportion of gas remaining in the gas cylinder at time t. By providing such a method, the average flow rate is determined based on previous measurements, and this is combined with a factor dependent upon the amount of gas remaining in the gas cylinder. Such a method enables a more accurate determination of the time to run out of the gas cylinder. |
