A temperature control system is designed to maintain the temperature at a constant value of 500 C inside an induction furnace.
126 Chapter 4
(a) The following test set of initial temperature measurements (once the furnace
temperature has reached steady state) is obtained: 507 502 520 500 492 485 499
495 497 500 516 501 489 503 490 481 504 511 499 512
Show that this is free of rogue data points and can therefore be used as a reference set against which to test future temperature measurements.
(b) The temperature is then measured at 10 min intervals and the following 20 measurements are obtained:
481 505 495 519 498 1015 508 477 500 526 501 488 502 492 464 503 499 510
515 497
Test whether there are any rogue measurements in this data set.

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?