Laboratory manual for the evaluation of non-automatic weighing devices

LG-3.11 Susceptibility to magnetism—Ferromagnetic loads

Table of contents


Sections 9, 10, 11 and 30 of the Specifications Relating to Non Automatic Weighing Devices (1998)


This test is performed on any complete weighing devices and load weighing elements that incorporate load cells functioning on the principle of "electromagnetic force compensation".



  1. Place a separator block of appropriate height on the load receiving element and zero the device. Place a test weight ≈½ Max made of a ferromagnetic material (iron or steel) on top of the separator block. Note the indication and remove the test weight.
  2. Remove the separator block, re-zero the device, place the test weight from step 1 directly on the load receiving element and note the indication.

Note: Separator block should be high enough to significantly reduce the effect on the test weight of any magnetic field created by the device. It should be lightweight, non-metallic and anti-static.

Interpretation of results

The DUT meets the requirements if the difference between the two indications is no greater than the in-service limit of error for that load.


Rev. 1 (March 2010)
  • AZSM renamed to AZT
  • formatting change
Rev. 2 (April 2010)
  • Complete revision to procedure
Date modified: