Q. What is the difference between a venturi meter and an orifice meter?

The main distinction between a venturi meter and an orifice meter is that the latter's orifice plate may be easily adjusted to accommodate varying flow rates whilst the former is rigid in the face of variations in that rate. While the primary distinction between the two is as described above there may be other distinctions that make the venturi meter more suited to monitoring larger flow rates than the orifice meter. Comparatively an orifice meter's coefficient of discharge will be low because of the large amount of energy lost whereas a venturi meter will be high since the losses are minimal.