A flow meter is an instrument that is used to measure the flow rate of liquids or gases. When buying a flow meter, the familiarity of the working personnel with the device and their experience with calibration is what one should take into consideration. One should also consider the maintenance factors such as availability of spare parts and the probability of failure. The cost of installation one should also take into consideration. One should not buy a device because it is less expensive since this can be the most costly installations. An installation engineer one can consult when buying the flow meters just in case there are any flow measurement challenges. Evaluating the nature of the process fluid and flow characteristics are the basics to selecting the best flow meters. Also, one should consider the piping and the area the flow meter is to be located.
The characteristics of the fluid to be considered are the pressure, temperature, viscosity, density and many others. These properties should have an indication of how they should interact for the flow meter to operate properly. A detailed composition of the fluid should also be there. This is to say that one should indicate whether the fluid has solids and whether they are soft or abrasive or whether they have big or small particles. So that one can select the best meter they should know the required meter range and this is done by identifying the minimum and maximum flows that will have to be measured. Over its full range the flow meter’s performance may not be accepted unless one knows the measurement accuracy. When one is purchasing a flow meter they should choose the ones without moving parts over the ones with them. Usually the flow meters with moving parts are a cause of problems and failure since the moving parts are prone to wear and tear. They also require clearance spaces for the moving parts that sometimes cause slippage into the flow being measured.
There are different types of flow meters which include; rotameters, piston flow meters, paddlewheel, turbine flow meters, ultrasonic flow meters and magnetic flow meters. The magnetic flow meters are available for in-line or insertion type. For any waste liquids that are conductive, they are ideal. The displays are usually integral and an analog output can be used or remote monitoring. Also the ultrasonic flow meters are used for dirty water or waste water. The principle of operation employs the frequency shift of an ultrasonic signal when it is reflected by discontinuities in the liquid flow. On the other hand the rotameter is the most used for liquids and gases.A Quick Overlook of Regulators – Your Cheatsheet