Hi David & Bert,
Thank you for pointing me in the correct direction. From the Mouser catalogue
I see that the disk at the front of the pot is called a servo mount.
The part that Bert suggests from Mouser has a 0.2% linearity whereas the stock
parts have a 0.1% linearity. The part from Mouser costs $113.88 CAD
I can get the ETI parts with 0.1% linearity directly from them for $213CAD
plus shipping.
Bert is it your experience that the 0.2% linearity parts are good enough for the job?
Thanks,
Laird
Laird A. Trimble, Ph.D.
President, Trimble Analytical Services Ltd.
laird.trimble_at_trimbleanalyticalservices.com
1-613-286-2799
> On Aug 10, 2025, at 10:40 AM, Spin-Doc wrote:
>
> Hi Laird,
>
> I have so far bought these Bourns potentiometers from Mouser, part number
> 652-3549H-1AF-103A
> They have a tendency of being a tiny bit (too) thick so it's a bit of a
> squeeze to get it in, but it does work.
> They come with that aluminium plate/disk installed, so they were not added later.
>
> Cheers
> Bert
>
>
>> Am 09.08.2025 um 23:48 schrieb Laird Trimble:
>>
>> Hi All,
>>
>> I've got a couple of old Agilent/Varian Zymark sample changers and it is
>> getting time to replace some of the potentiometers used for sensing lift,
>> reach, and rotation positions. I have the following official unused Agilent
>> replacement parts:
>>
>> Lift: Bourns Hybritron 3541H-471-103L RES 10Kohm +/- 10%, LIN +/-0.1% (Agilent Part No. 1901089800)
>> Reach: Bourns Hybritron 3541H-470-103L RES 10Kohm +/- 10%, LIN +/-0.1% (Agilent Part No. 1901099200)
>> Rotation: Bourns Hybritron 3541H-472-103L RES 10Kohm +/- 10%, LIN +/-0.1% (Agilent Part No. 1901089900)
>>
>> All three pots appear to be 10Kohm ±10% with a ±0.1% linearity.
>> And yet they have slightly different Bourns and Agilent part numbers. As
>> far as I can tell electrically they are the same part. I am curious, are
>> they the same? Will any 10 turn linear 10Kohm pot with the same linearity be
>> a suitable replacement?
>>
>> Several SMS robots that I have opened have pots manufactured by ETI Systems,
>> part number MH22S-10. These pots have the same electrical characteristics
>> and linearity as the Bourns part but the ETI parts used at all three locations
>> have the exact same part number. This leads me to think that all three
>> Bourns pots are essentially the same thing.
>>
>> Finally, the pots used in the SMS have a disk that is attached to the body
>> that is used to secure the pot to the SMS housing rather than the screw
>> type mount that is more common for this type of pot. Does anyone know if
>> this ring is installed by Agilent/Varian or by the original manufacturers?
>>
>> Thanks all for your help.
>
> Magnetic resonance equipment, service, training & more
> Selling & buying used NMR equipment (all vendors)
> Dr. rer. nat. Bert Heise
> Owner, Applications Scientist
>
> Spin-Doc Bert Heise
> Kiefernweg 13
> 58239 Schwerte
> Germany
> Mobile: +49 171 5135315
> Email: bert.heise_at_spin-doc.net
> Web: http://www.spin-doc.net
>
> Representing:
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> MestreLab NMR Software (http://www.mestrelab.com)
> Barthel HF Amplifiers (http://www.barthel-hf.de)
>
>
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Received on Sun Aug 10 2025 - 13:37:37 MST