Hi Recently performed a very basic fluid mechanics experiment with water flowing at different speeds through a Venturi Rig. Most of it went as expected, total head stayed roughly the same throughout but slightly decreased from flow loss due to resistant forces. However, at certain random points the total head would increase further along the Venturi. I know it is most probably imperfect experimentation technique. What could have caused this increase in the total head further along the pipe?? I'm a bit confused. Thanks in advance for any light that can be shed on this.