[Amps] Alpha vs Henry

[Roger (sub1)]

On 4/9/2011 12:32 PM, Ron Youvan wrote:
> Patrick AA6EG Barthelow wrote:
>
>> This is an interesting one... can someone point their IR thermometer gun at a room temp object and then take a hair dryer on hot,
>> and blow it across the field of view, and report results?  Tnx

I've used IR imaging systems that could show the heat rising from a 
cigarette and in the early days we cut the top off DRAM DIMs and used 
them for imaging.  Those would even show the heat rising from a 
soldering iron on a fairly low temp no where near enough to melt solder.

The imaging systems will show the temp variations in the rising air.
OTOH as John says, the question is immaterial because (paraphrased) the 
tube will be hotter than the air leaving it.

One other point, I've seen the question raised about how much pressure 
was a fan generating.  For a given tube and existing system you can 
treat air flow and pressure the same as voltage and current.  IF you are 
getting the required air flow you MUST have the required air pressure. 
Insufficient pressure and you will have insufficient flow.  Get the 
proper flow and you will have the proper pressure.

IF the radiator is plugged or partially clogged you will have high 
pressure and low flow. But again, it the flow if proper then so is the 
pressure.

73

Roger (K8RI)


>     I can, if I can remember all the way to Monday morning, but the question is immaterial, because:
> "The temperature of air leaving a tube, can not exceed that which is heating it."