Electromagnetic flow meter An electromagnetic flow meter is an induction type flow instrument often used to measure the volumetric flowrate of a conductive medium based on Faraday’s Law in closed pipelines. Faraday’s Law states that the voltage induced across any conductor as it moves at right angles through a magnetic field is proportional to the velocity of that conductor. There is one important point when using electromagnetic flow meters. Because electromagnetic flow meters are based on the laws of electromagnetic induction, conductive liquids are the only liquids for which flow can be detected. Whether it is a conductive liquid or not is determined by the presence of electrical conductivity. So, just what is electrical conductivity? Electrical conductivity generally is a value that expresses the ease for electricity to flow. The opposite numerical value is resistivity, which expresses the level of difficulty for electricity to flow. For units, S/cm (siemens per centimeter) is primarily used. To determine how easily electricity will flow, 1 cm² electrodes are placed 1 cm apart. Using tap water at 100 to 200 μS/cm, mineral water at 500 μS/cm or more, and pure water at 0.1 μS/cm or less as samples, we can provide examples of actual measured electrical conductivity. As per CGWA Guidelines ground water withdrawal without the installation of tamper-proof digital water flow meters and telemetry (wherever applicable) shall be construed as illegal. Non-compliance of these conditions shall invite a Penalty provision and/or Environmental Compensation against the proponent for illegal withdrawal of ground water as per the CGWA Guidelines and may result in cancellation/rejection of NOC and sealing of ground water abstraction structures. Installation of Digital Water Flow Meter on Ground water abstraction structures Allegiance Water Management www.allegianceindia.in