Patent ID: 7519482

Claim:
A multi-variable mass/flow rate transfer device comprising: a differential pressure/static pressure/temperature calculating unit for calculating a differential pressure value, a static pressure value and a temperature value in real time based upon a signal detected from a process; an instantaneous flow rate calculating unit for calculating an instantaneous flow rate based upon the differential pressure value, the static pressure value and the temperature value; an accumulation counter for accumulating the calculated instantaneous flow rate of the instantaneous flow rate calculating unit to produce an accumulated flow rate; an accumulated flow rate alarm unit for producing an alarm when the accumulated flow rate produced by the accumulation counter becomes a predetermined value, and wherein both an upper limit threshold value (S 1 ) and a lower limit threshold value (S 2 ) of the accumulated flow rate alarm unit satisfy the below-mentioned formulae with respect to the instantaneous flow rate (A), a flow rate precision percentage (±a [%]), an error (±B) of the accumulated flow rate and an elapsed time (t): S 1 =A·t ·((100+ a )/100)+ B, S 2 =A·t ·((100− a )/100)− B.