Characteristic: 1 software calibrating produces speed quickly(Producing speed is the 5 times that electric resistance calibrates) 2 outer-ring components are few , the chip and sensor price advantage are obvious , complete machine cost has most competition; 3 consume the electricity is few , a battery service time is for 3 years the above; 4 pressure units may choose arbitrarily and constitute (PSI , Bar ,KPA,Kg/cm2), but are sold to any place; 5 functions stabilize , measure a precise;