Dear Geoff,


Hang in there, I have to trawl through my filing cabinet since I haven't
got a 253 myself.

However, I would advise against attaching your multi-meter to the
connectors on the circuit board. The reading you might get will reflect
the resistance of circuit board rather than the filament and the test
current from the multi-meter might potentially damage your circuit
board.

You have to switch off the source first and then remove the cover on the
source flange that houses all the supply cables (wires). Disconnect the
two supply cables from the filament feed throughs and measure across the
feed throughs. The resistance should be about 1 Ohm give or take 0.5
(the actual value is not that important as long as there is a
resistance).

The moment I'll hit pay-dirt in my filing cabinet, I will let you know
the which feed throughs we're talking about. In the meantime, have a
look in your manual. There should be a schematic of the source and the
source feed throughs somewhere.


All the best,

Wolfram




> From: Stable Isotope Geochemistry
> [mailto:[log in to unmask]] On Behalf Of Geoff Garrison
> Sent: 21 January 2004 19:50
> To: [log in to unmask]
> Subject: MAT 253 source
>
>
> Can anyone tell me how to check the resistance across the
> source filament on a MAT253? I know it's two of the leads off
> one of the circuit boards, I just don't know which.
>
> Thanks,
>
> Geoff
>
> -------------------------------------------------------------------
> Geoffrey Garrison
> Associate Researcher
> Department of Earth and Space Sciences
> University of Washington
> Box 351310
> Seattle, WA 98195
> [log in to unmask]
> http://www.ess.washington.edu/People/faculty_b> io/garrison-bio.html
>