- Explosive hazardous environment
Generally, the instrument is used in an explosive environment, and an instrument that is suitable for the atmosphere of the place of use, the classification, and grouping of the explosive mixture, the type of equipment, and other safety rules or standards should be selected.
- External magnetic field
Industrial automation instruments generally have technical indicators required to resist the influence of external magnetic fields, and they are required to be able to influence the amount of no more than the specified value under the magnetic field strength of 50Hz AC and DC 400A/m.
There is no such index in the electromagnetic flowmeter standard, and the installation manual of the manufacturer usually only qualitatively requires that there is no strong magnetic field equipment such as large motors near the meter. There is not much practical experience in the influence of magnetic fields. There are occasional cases where the application fails due to installation location restrictions or engineering design errors.
For example, the electromagnetic flow sensor is installed about 1m away from the thousands of volt AC steelmaking furnace. However, there are also instances where 8m away from the hundreds of volt AC transformers does not significantly affect the measurement and the work is still possible in the thousands of watt DC steelmaking furnaces at a distance of 3m, but measures to prevent heat radiation and heat insulation must be taken.
- Ambient temperature and humidity
The electronic components of the instrument will be affected by the ambient temperature and change the measurement performance. Some models list the temperature influence coefficient, but most do not have this index. If the ambient temperature at the installation site of the flow sensor is not ideal, the integrated type should not be used, and the separated type should be selected to reduce the impact of the ambient temperature on the electronic components.
High humidity will accelerate atmospheric corrosion and electrolytic corrosion, reduce electrical insulation; low temperature is prone to electrostatic interference. Changes in ambient temperature can cause humidity problems. Expect the range of possible changes during use, and verify whether it will cause problems during operation.
- Electrical interference
Power cables, motors, and electrical switches all produce electromagnetic interference and become sources of errors.