[volt-nuts] Resistance standard

[Rob Klein]

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.