No the cart magnetic field will not affect a scale.
If you use a scale with a metla tray, slip a piece of thin plastic, or hard paper on the metal scale tray. so the cart tip is not harmed. then reset the scale calibration to include the paper at zero grams.
Arrange the scale tray to be at the same height as the arm would be playing LPs... to set the arm weight.
My scale wears out the battery when not used for a long time. So maybe take the battery out when finished if not using for awhile again.
If you use a scale with a metla tray, slip a piece of thin plastic, or hard paper on the metal scale tray. so the cart tip is not harmed. then reset the scale calibration to include the paper at zero grams.
Arrange the scale tray to be at the same height as the arm would be playing LPs... to set the arm weight.
My scale wears out the battery when not used for a long time. So maybe take the battery out when finished if not using for awhile again.