… measuring or checking the flow, level, pressure or other variables of liquids or gases (for example, flow meters, …
Explanatory notes
… measuring or checking the flow, level, pressure or other variables of liquids or gases (for example, flowmeters, … of the Nomenclature, such as : (a) Pressure‑reducing valves and thermostatically controlled valves ( heading … apparatus generally incorporates an element sensitive to variations in the quantity to be measured (e.g., Bourdon …