Composition of the mixture
The composition of the fuel initially filled into the tank.
This option is relevant primarily for gas cylinders (see "Type"). In them, different mixtures will differ primarily in the temperature regime of operation (see below). They can also have different temperatures and specific heat of combustion, but this difference is not very large, and when used for its main purpose (cooking, heating water) it is almost imperceptible. Therefore, it makes sense to pay attention to the composition if the cylinder is planned to be used in cold conditions — in winter or in the highlands — or for specific purposes (for example, some models allow installation in a blowtorch). If there is no question of such use, then the composition of the mixture practically does not play a role (except that it is worth considering that branded “winter” grades of fuel are more expensive than “ordinary” ones).
Detailed data on various compositions of the mixture, if desired, can be found in special sources.
Net weight
The weight of the fuel filled into the cylinder, excluding the tank itself. Knowing the approximate fuel consumption in the burner, this parameter can be used to estimate how much the reserve in the cylinder will last. The weight of the tank itself is rather small compared to the weight of the fuel, and can usually be neglected when calculating the total weight of the luggage.