Determining method of actual zero point and actual measuring range of differential pressure transmitter

The invention provides a determining method of an actual zero point and an actual measuring range of a differential pressure transmitter, which comprises the following steps of: obtaining a first actual liquid-level value and a first differential pressure value of positive and negative pressure chambers of the differential pressure transmitter corresponding to the first actual liquid-level value; obtaining a second actual liquid-level value and a second differential pressure value of positive and negative pressure chambers of the differential pressure transmitter corresponding to the second actual liquid-level value; and determining the actual zero point and the actual measuring range of the differential pressure transmitter according to the first actual liquid-level value and the second actual liquid-level value and the first differential pressure value and the second differential pressure value. A determining method of an actual zero point and an actual measuring range of a double-flange differential pressure transmitter for measuring a level position of a mixture is also provided. The determining method of the actual zero point and the actual measuring range of the differential pressure transmitter effectively resolves the problem that in a differential pressure transmitter of the prior art an error exists between an indicating value and the actual liquid-level value.