Each type of meter has its own characteristics, and there is no perfect flow meter . The selection of flow meters (flow meters) often plays an important role in the successful use of the meters. Due to the complex conditions of the measured objects, the variety of meters, and the performance indicators, the selection of the meters is difficult. The purpose of selection is to choose the most suitable flow meter from the many varieties and avoid the disadvantages.
(I) The steps of selecting the flowmeter instrument are as follows:
1. Primary selection of available instrument types based on fluid types and five considerations (there are several types to choose from);
2. Collect data and price information for the primary selection type, and prepare conditions for in-depth analysis and comparison;
3. Use the elimination method to gradually focus on 1 or 2 types. Repeatedly compare and analyze the five factors to determine the pre-selection target.
(2) General selection of flow meters ( flow meters):
Can be considered from five aspects, these five aspects are meter performance, fluid characteristics, installation conditions, environmental conditions and economic factors. The five factors are detailed as follows:
1. Instrument performance: accuracy, repeatability, linearity, range, flow range, signal output characteristics, response time, pressure loss, etc.
2. Fluid characteristics: temperature, pressure, density, viscosity, chemical corrosion, abrasiveness, fouling, miscibility, phase change, electrical conductivity, sound velocity, thermal conductivity, specific heat capacity, isentropic index;
3. Installation conditions: pipeline layout direction, flow direction, length of the straight pipe section on the upstream and downstream sides of the test piece, pipeline diameter, maintenance space, power supply, grounding, auxiliary equipment (filters, aerators), installation, etc .;
4. Environmental conditions: ambient temperature, humidity, electromagnetic interference, safety, explosion protection, pipeline vibration, etc.
5. In terms of economic factors: instrument purchase costs, installation costs, operating costs, calibration costs, maintenance costs, instrument life, spare parts, etc.