If the primary selection has been determined to adopt the electromagnetic flowmeter measurement method, the instrument selection becomes the specific electromagnetic flowmeter selection, and several factors in the five aspects of the appeal must be reconsidered. However, the focus of consideration has shifted from the selection of instrument varieties to the comparison and selection of electromagnetic flowmeter models. Some factors do not need to be considered, such as viscosity and lubricity in fluid characteristics, gas compression coefficient, pressure in instrument performance, etc. According to the characteristics of electromagnetic flowmeters, the selection considerations are shown in the figure.
| Instrument performance | Accuracy, repeatability, range, flow rate, flow rate range, material in contact with fluid, signal output characteristics, response time |
| Fluid characteristics | Conductivity, fluid working conditions (pressure, temperature), heterogeneous (solid or gas) content, flow state, chemical properties (corrosive), electrochemical properties, abrasiveness, dirt, and fouling |
| Installation conditions | Pipeline layout, fluid direction, upstream and downstream resistance (disturbance) fluid conditions and straight pipe sections, pipeline vibration, maintenance space, grounding |
| Environmental conditions | Ambient humidity, ambient temperature, ambient atmosphere (explosion-proof requirements), safety, pipeline stray current, electromagnetic interference |
| Economic aspect | Instrument purchase cost, installation and commissioning cost, maintenance cost, inspection cost, service life, operating cost, spare parts |