Class A(circular graduation at main points) The tolerances are half of the tolerances of class B according to DIN ISO standards.
Class A conformity certified (circular graduation at main points): Conformity means compliance with the German Calibration Regulations and the relevant standards. By imprinting the conformity symbol ”H” we confirm that the measuring device complies with these conditions. A batch certificate of conformity is supplied together with every box. On request individual certificates of conformity are available.
Graduation:
the blue graduation is fused on the glass and resistant against most acid and alkaline solutions
the amber stain graduation penetrates into the glass surface and is, therefore, more resistant than the blue, fused-on enamel graduation