The flow rate of liquids and gases is measured by the use of an instrument that is known as a flow meter. 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. Also one should take into consideration the cost of installation of the flow meter. A device because it is less expensive one should not buy since this can be the most costly installations. When buying the flow meters one can consult an installation engineer just in case there are any flow measurement challenges. The basics to selecting the best flow meters are evaluating the nature of the process fluid and the fluid and flow characteristics. 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. Of how they should interact these properties should have an indication for the flow meter to operate properly. There should also be a detailed composition of the fluid. 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. One should know the required meter range so that they can select the best meter and this is done by identifying the minimum and maximum flows that will have to be measured. The flow meter’s performance may not be accepted over its full range unless one knows the measurement accuracy. The flow meters without moving parts one should choose over the ones with them when purchasing flow meters. A cause of problems and failure are the flow meters with moving parts since they are prone to wear and tear. They also require clearance spaces for the moving parts that sometimes cause slippage into the flow being measured.
Different types of flow meters are there and they include; rotameters, piston flow meters, paddlewheel, turbine flow meters, ultrasonic flow meters and magnetic flow meters. Available for in-line and insertion type the magnetic flow meters are. Ideal they are for any waste liquids that are conductive. Usually the displays are integral and an analog output can be used or remote monitoring. For dirty water or waste water the ultrasonic flow meters are also used. The frequency shift of an ultrasonic signal when it is reflected by discontinuities in the liquid flow is the principle of operation that is employed. The most used for liquids and gases on the other hand is the rotameter.The Ultimate Guide to Resources