TURBO button and lamp . the button allows the nitrogen gas flow rate to be adjusted between a NORMAL VALUE(5 L/min except at temperatures below 90 K) and a 'turbo'value(10 l/min except above 310 k) . if the turbo lamp is OFF this indicates normal flow , whereas ON indicates turbo flow . in addition , during a coll phase the turbo lamp will flash .this indicates a 'machine turbo', in which the cryostream fixes the flow rate at the turbo value in order to minimise the cooling time.