2 Attachment(s)
Ammeter movement adjustment ( or repair ).
[SIZE=4][FONT=arial]Dear Sirs
I have a problem with an ammeter movement ( moving coil, permanent magnet ) that I need to repair.
Electrically the movement is working fine.
I adjust the mechanical zero, the movement is connected to the calibrator and the needle deflects to full scale deflection according to specs.
The problem is, when the energy is removed, the needle doesn’t return to zero every time.
Sometimes it rests above the zero mark ( most of the time ), others below.
I have checked if the coil frame rubs against the core, or if there is friction between the frame pivots, but everything seems to be all right, moving freely.
I am not sure if the movement was “ serviced “ by someone before…
Can you give me some insight about what should I look for in order to put the movement working properly ?
Thank you very much in advance for any help you could provide.
Hope to hear from you soon.
[B]P.S.-[/B] The movement is part of an analogue ammeter made by Chauvin Arnoux, model CA 401[/FONT][/SIZE]