Different types of flow meters have different requirements for the choice of installation location. Where to install the specific flowmeter, you need to decide according to the product you purchase.
Such as electromagnetic flowmeter.
1. Choice of installation site:
　　·Choose a place where there is no negative pressure in the measuring tube;
　　·Avoid installing in strong electric equipment accessories such as motors, transformers, etc., to avoid electrical interference;
　　·Avoid places with strong corrosive gas around the installation location;
　　·When measuring mixed-phase fluids, avoid places that cause phase separation;
　　·The ambient temperature should generally be within the range of -25℃～60℃, avoid direct sunlight as much as possible;
　　·Installed in a vibration-free or small vibration environment, if the vibration is too large, fixed supports should be added to the pipes before and after the sensor;
　　·The relative humidity of the environment should be within the range of 10%～90%;
　　·Avoid installing in a place that can be directly drenched or submerged by rain;
2. Requirements for the length of straight pipe section: (D is the inner diameter of the flowmeter)
The electromagnetic flowmeter has relatively low requirements for the front and rear straight pipe sections. Generally for 90° elbows, T-shaped tees, reducers, fully open valves and other flow resistance parts. There should be a 5D straight pipe section away from the center line of the electrode axis of the electromagnetic flowmeter (not the end face of the sensor).
For valves with different opening degrees (such as valves with adjustable opening degrees), the length of the upstream straight pipe section needs to be 10D. One
Generally, the straight pipe downstream of the sensor only needs 3D to meet the requirements. When measuring mixed liquids of different media, the distance between the mixing point and the flowmeter must be at least 30D.
3. Installation position and flow direction:
The electromagnetic flowmeter can be installed on the pipeline horizontally, vertically and obliquely

The flow meter itself does not have a control function. The flowmeter can output signals according to the requirements of your control system. Such as 4-20mA, pulse signal, etc. And HART or, RS485, etc.
If you need a flow meter with a switch output function, it should be a flow switch.

Generally speaking, the accuracy of mass flow meters is the highest. What is measured is mass quantity, which is a flow meter often used as a trade settlement.
The flowmeter can generally reach 1.0 level, and 0.5 level is considered high accuracy. The accuracy of liquid flow meters is generally 0.2%-0.5%.
Of course, the accuracy of the flowmeter still depends on the site conditions. If the measurement of temperature and pressure is not very difficult, the accuracy of the flowmeter must be relatively high. In addition, to ensure the accuracy of the flowmeter, correct installation and use are also very important.

The cleaning method of the flowmeter should be determined according to the type of the flowmeter and the measured medium. It can be rinsed with water, or a cleaning solution can be used according to specific conditions. It is best to remove and clean.