[Amps] sealed air cooled dummy load in oil??

[Dr. David Kirkby]

Jim Nowotarski wrote:
>>Date: Tue, 04 Apr 2006 12:21:52 -0400
>>From: "Gary Patterson" <gpatterson53 at hotmail.com>
>>Subject: [Amps] sealed air cooled dummy load in oil??
>>To: amps at contesting.com
>>Message-ID: <BAY101-F247E2BA4F3BEF3ADD40EEDDACA0 at phx.gbl>
>>Content-Type: text/plain; format=flowed
>>
>>Can one of those "finned", air cooled, sealed dummy loads be dumped
> 
> into a
> 
>>can of transformer oil (cantenna-like) and significantly increase
> 
> its power
> 
>>dissapation??
>>
> 
> Generally yes, depending of course on your definition of
> "significant."
> I would suggest monitoring the temperature of the load. The oil will
> help transfer the
> heat from the load, but of course it won't increase the max
> temperature that the load can take.
> -
> Jim


I agree with Steve - it depends a lot of the construction. It may make a lot of 
difference, or it may make very little.

But you have an interesting point there about monitoring temperature. But one 
would need to monitor the resistor not than the case.

Perhaps there would be some millage in using a *good* [1]  DVM and monitor the 
change in resistance of the resistor. Just ensure the change in resistance 
caused by the temperature coefficient is no higher than occurs with air cooling 
at max load. That is not perfect, as local hot spots could occur on the 
resistor, but it is certainly better than case temperature.

[1] Absolute accuracy not important, but good resolution would be. There are 
many lab grade DVMs on eBay for next to nothing. 5 1/2 digits would not be 
expensive.