Tsinghua University conducted CTOD tests on common bridge steels Q370qE and Q345qD, and calculated the CTOD values of materials under brittle fracture, ductile brittle failure and ductile failure respectively, as the basis for revising the conventional impact toughness standard.

(1) The output of the electromagnetic flowmeter is only proportional to the uniform velocity of the measured medium, and has nothing to do with the activity condition (laminar flow or turbulent flow) under the symmetrical distribution. Therefore, the measuring range of electromagnetic flowmeter is extremely wide, and its measuring scale can reach 100:1, and some even reach 1000:1 operational flow scale.