On 11-06-20 10:11 PM, Abd ul-Rahman Lomax wrote:
At 04:10 PM 6/20/2011, Stephen A. Lawrence wrote:
Aw, these reports drive me nuts. I'd not read this one, I think.
They have a pump for cooling water, it seems. So when they start up,
they are pumping an estimated 6.47 kg per hour of water. They assume
that this flow rate remains the same. Why?
It's a constant displacement pump. That's what it does.
Sure. But does it pump the same regardless of back pressure?
YES -- That's exactly what it does! That's the whole point -- you can
use it for calorimetry because its flow rate is unchanged! You can't do
that with pumps that don't have a predictable flow rate.
It's like the thing found in the basement of East Campus, labeled "1 Amp
-- No Matter What".
Did they record the number of pump cycles per minute more than at
initiation? Imagine that the pump has a leak in its internal
mechanism, say a leaky flap valve.
Oh, for goodness sake. And every time they run the test they happen to
use a defective pump, eh?
Suppose the reservoir has a leak, too, while you're at it, and nobody
noticed the wet floor.
They also weighed the reservoir before & after, as a double check. You
can forget about varying flow rates -- there is no evidence to support
the idea.
