This is best done at the early design stage where changes to the overall system design can be made to alleviate or reduce any magnetic disturbance effects on the DMC. The DMC magnetic compensation procedures can then reduce the effect to being negligible, but it is far better to reduce disturbances to a minimum in the first place.
Find a place in the host system that is magnetically stable. You can check any change of magnetic fields at the intended mounting place using our demo program or by monitoring the DMC readings.
Frequent changes of the magnetic field strength can be caused by:
- Movable magnetic parts (which are moved or rotated during operation, such as stepper motors, focusing systems etc.
- Non-constant currents, if they are active during the DMC measurement. This includes also “constant” currents, which may depend on battery voltage. In addition, unstable current loops caused by an unclean system grounding can interfere with the DMC.
- Strong magnetic materials obviously have an effect, especially if large temperature changes are to be expected. A typical change of 1% – 2% per 10°C can be expected.
If such problems are identified, we recommend the following mitigation checks:
- Remove the magnetic part or replace it with non-magnetic equivalent
- Increase the distance between the DMC and the offending part
- Shield the disturber, but do not shield the DMC
- Use two-wire, twisted pair or coaxial cables
- Choose an optimal geometry of cables relative to DMC
- Remove current loops with a clean system grounding concept
- Choose timing of currents and DMC measurement optimally
- Re-compensate by hand (e.g. after battery change)
If you need any further support, our DMC experts will be happy to provide you with more information.
Simply use the contact form to get in touch.