To make accurate measurements, you must frequently degaussing and balance the probe. Degaussing can eliminate the parasitic magnetic field in the core of the probe, otherwise it will cause zero drift and measurement error. After each degaussing, the zero balance of the probe should be adjusted to eliminate the deviation. Degaussing and balancing are required under the following conditions:
After 20 minutes preheating each time you turn on the oscilloscope;
Whenever there's an overload;
Each time the probe is exposed to a strong magnetic field;
Each time no-load dc bias is found to be non-zero.