Combined flow metering and sampling instrument - uses hollow cam together with rheostat and motor to achieve continuous sampling

摘要

The apparatus combines a flow measuring instrument and a sampling device within a single instrument and is used for pollution measurement. It is possible using solely mechanical means to obtain linear recordings of flow together with continuous sampling proportional to the instantaneous flows. Level variations are transformed using a specially designed hollow cam (2) into horizontal displacements proportional to flow. Flow variations are transformed directly by a rheostat (8) into variations of potential difference which in turn produce variations in the speed of rotation which in turn (9) which actuates the sampling system. The sampling is continuous and includes material in suspension without high speed pumping.