[volt-nuts] Resistance standard

[Mitch Van Ochten]

Hi Rob,

ESI recommended "Drakeol 9 LT mineral oil" in their literature which I 
couldn't find in small
quantities.  I investigated a synthetic oil replacement called SpectraSyn 
PAO and Exxon offered
to send a sample.  After checking with a chemist at work I decided not to.
He said over many years of immersion the "long chain parrafin" as Mike 
mentioned would be the best, and
less likely to deteriorate the insulation than the synthetic replacement.

I have attached a chart he sent me for the group's observation.

Mitch


----- Original Message ----- 
From: "Rob Klein" <rob.klein at smalldesign.nl>
To: "Discussion of precise voltage measurement" <volt-nuts at febo.com>
Sent: Monday, August 22, 2011 8:10 AM
Subject: Re: [volt-nuts] Resistance standard


> Hi Mike and Charlie,
>
> For the oil, I have decided on the stuff that is sold locally as "sewing 
> machine oil". This is a highly refined light mineral oil, guaranteed to be 
> acid free.
>
> As explained in my previous message, things haven't been progressing over 
> the last 18 months, but I'm going to pick it up again soon, so stay tuned.
>
>
> Best regards,
> Rob.
>
> Op 23-7-2011 19:14, Charles Black schreef:
>> Hi,
>>
>> The traditional oil for standard resistors and oil baths is Mineral Oil. 
>> The cheapest source of Mineral Oil USP  for small quantities is out local 
>> grocery store at about $5.50 per pint. It is a highly purified paraffin 
>> oil. If you need a large quantity then check out Exxon Marcol 72 which is 
>> available for about $12 per liter from Measurements International. I am 
>> trying to find a much better price since I could potentially use 157 
>> liters if I am able to get a used bath that I know of.
>>
>> Charlie
>>
>> On 7/23/2011 3:03 AM, m k wrote:
>>> Hi,
>>>
>>> I only recently joined this group, but in answer to rob, the best oil 
>>> would be a long chain parrafin, can be purchased for vacuum pumps, also 
>>> a solid encapsulation will shift as it ages, and that would put strain 
>>> on the resistors, so they would need an initial wrap in a silicone 
>>> perhaps? definately a very compliant cover of some sort to isolate the 
>>> strain.
>>>
>>> Mike
>>>
>>> PS I am shortly going to set up some LTZ's for a small family of 
>>> references to age and compare. Doing the sums a difference measure 
>>> between each one and graphed will tell me which ones are the most 
>>> stable, then after a year or so splash out and get one calibrated 
>>> against a known source.
>
>
> _______________________________________________
> volt-nuts mailing list -- volt-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> and follow the instructions there. 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pic27550.jpg
Type: image/jpeg
Size: 45042 bytes
Desc: not available
URL: <http://www.febo.com/pipermail/volt-nuts/attachments/20110822/b4fa32bc/attachment-0001.jpg>