At  particular radius  of  insulation over  a  cylinder,  loss of heat is maximum.  The unit

consists of a G.I. pipe provided with plaster of Paris insulation on out side surface. Four

pipes are provided with heater inside having input control. Input to heaters is measured

by common voltmeter and ammeter, by controlling input to heaters, it is shown that critical

radius of insulation is ratio of thermal conductivity and outside heat transfer co-efficient.

SPECIFICATIONS:

1.  G. I. Pipes with electrical heater inside - 4 Nos.

2.  Insulation over the pipes of different thickness.

  a)   Dimmerstat 2A,    b)  voltmeter and ammeter to measure inputs to heater.

  c)  Digital temperature indicator to measure temperatures across insulation.