On differential pressure switches in metric and imperial systems
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The company usually uses Dwyer differential pressure switches in metric format; now it needs to switch to imperial format. I would like to ask whether the model number needs to be changed, or whether only the pressure range needs to be adjusted to imperial units.
Why change it to the imperial system? It is very likely that both the mechanical interfaces and electrical interfaces will differ. If there are no scales, then there should be no significant difference between metric and imperial systems; it’s just that different manufacturers may have different dimensional specifications for their products.
Our country uses legal units of measurement; the imperial system is not a legal unit and its use is prohibited in our country. Why is there a need for change?...
Is there such a requirement? How come I didn’t know?
Article 3 of the Metrology Law of the People’s Republic of China: **The International System of Units shall be adopted. The units of the International System of Units and **other selected units are** the legal units of measurement. **The names and symbols of legal units of measurement are announced by the State Council. Non-**legal units of measurement should be abolished. The measures for abolition shall be formulated by the State Council.
It was later explained in detail by the company’s management that when selecting the model, we used imperial units for the range values, and then converted them to metric units before making the selection