I remember visiting the metrology lab in HP Palo Alto (Glen Whatshisname) when I worked for them in the early 70s. There was a set of toggle switches on the wall; for every person inside, one switch was turned on. I don't know how well it worked but apparently, well enough for 1970s-vintage metrology.
Jeremy On Wed, Nov 1, 2017 at 11:08 AM Attila Kinali <att...@kinali.ch> wrote: > On Wed, 1 Nov 2017 15:37:38 +0100 > Magnus Danielson <mag...@rubidium.dyndns.org> wrote: > > > Silly people > > want a relative comfortable temperature and well, building A/C is > > typically bang/bang regulated so you get what you paid for. > > My short stint in the HVAC business taught me, that it's surprisingly > difficult to stabilize room temperature to better than 2-5°C. > It starts at such simple things as measuring the temperature. > The position of the sensor and its distance to the wall make a huge > difference. Just 1cm further away from the wall, or 10cm up or down and > you get 2-3°C difference. An A/C system usually controls the temperature > of the air inlet, which is the simplest thing to do, but actually you want > to control the (heat) power flow into the room. And this is something that > has not been possible with standard equipment until recently. > > The best we can do today is to have a well insulated room (no windows > with whith unknown power flows) and measure the temperature at a few > strategically choosen points. Then control the heat influx and > outflux using an approriate control loop. This will still result > in deviations of 1-2°C when somone walks in. > > > Attila Kinali > > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Sent from my iPad 4. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.