Every In-Check DIAL is individually calibrated to ensure a high degree of accuracy; it's accurate to +/- 10% or 10 L/min (whichever is greater)

Inspiratory flows in the range of 15 L/min to 120 L/ min can be measured

Tested by AEA Technology P.L.C. in the U.K. for accuracy, and has been verified as providing similar resistances to inhaler devices