| 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. |
