Electromagnetic flow meter are widely used in the measurement of various conductive media, such as clean water, sewage, liquid acid, alkali, salt, liquid organic chemical products, soy sauce, vinegar and wine in the food industry, etc. Applesauce mixed with lumpy pulp and concrete mixed with sand and gravel, these slurry mixtures can also be measured, but various highly corrosive media need to be equipped with corrosion-resistant engineering materials, such as rubber, polytetrafluoroethylene, etc. as the lining of the flowmeter. Sauces mixed with bubbles and solid substances require special calculation methods to reduce measurement errors.

The Following Factors Should be Considered when using Electromagnetic flow meter:
(1) Consider the conductivity of the fluid. The minimum conductivity required should refer to the manufacturer's recommendations. Generally, the conductivity is required to be 5 to 20μS/cm.

(2) The choice of lining material, generally there are several optional materials such as PTFE, PFA, ceramics and rubber.

①PTFE is the most commonly used lining material. Because it cannot be pasted on the inside of the shell, it is not suitable for vacuum conditions. At the same time, some liquids can penetrate PTFE, causing short circuits and corrosion to flowmeter components;

②PFA, which has lower permeability than PTFE, but is easily deformed when temperature and pressure change;

③Ceramic, which is suitable for a variety of application conditions, but this material is sensitive to temperature fluctuations and pipe stress;

④Rubber, neoprene or natural rubber is the cheapest lining, mainly used for water measurement;

(3) When selecting the electrode material of the electromagnetic flow meter, not only the corrosion resistance to the measured medium should be considered, but also the avoidance of electrode surface effect should be considered.

1. Molybdenum-Containing Stainless Steel (OCr18Ni 12M02Ti)

For industrial water, domestic water, and sewage treatment. It is resistant to weakly corrosive media and can be widely used in the petroleum, chemical, urea, and vinylon industries.

2. Tungsten Carbide-Coated Stainless Steel

For non-corrosive, highly abrasive media.

3. Hastelloy B (HB)

Alkali-resistant, offering excellent corrosion resistance to hydrochloric acid at all concentrations below its boiling point. It also resists non-oxidizing acids, alkalis, and non-oxidizing salt solutions, such as sulfuric acid, phosphoric acid, hydrofluoric acid, and organic acids.

4. Hastelloy C (HC)

Resists corrosion from acids and oxidizing acids, such as nitric acid, mixed acids, or mixtures of chromic acid and sulfuric acid. It also resists corrosion from oxidizing salts, such as Fet, Cut, or other oxidants. This includes corrosion from hypochlorite solutions and seawater above ambient temperature.

5. Titanium (Ti)

It is resistant to corrosion from weak acids and weak bases, seawater, various chlorides and hypochlorites, oxidizing acids (including fuming nitric acid), organic acids, and alkalis. It is not resistant to purer oxidizing acids (such as sulfuric acid and hydrochloric acid). However, corrosion is not significantly reduced if the acid contains oxidizing agents (such as nitric acid, iron, and cutter).

6. Tantalum (Ta)

It has excellent acid resistance, similar to glass. With the exception of hydrofluoric acid, fuming sulfuric acid, and alkalis, it is resistant to almost all chemical media (including hydrochloric acid, nitric acid, sulfuric acid, and aqua regia).

7. Platinum-iridium alloy

It is suitable for almost all chemicals, but is not suitable for aqua regia and ammonium salts.