Measurement of the gas volume based on the flow velocity when purging of gas lines in combination with the Mobile Gas Flare S (402280), the Mobile Gas Flare M (402380) and the Mobile Gas Flare L (402480). This option requires the pressure measurement option (282124 or 282135) for the OLLI (280000/280040/280060). The V measurement for propane only works with the Sensor Array option (282102), NOT with the Dual IR Sensor option (282103).