Thermal Insulation Icy Copper Can

Copper in freezer  a least 2h.add crushed ice (fill up about 2/3 of a can)              Energy meters(6A6), Immersion Heaters(6B1), copper calorimeters(6B1)

                                                                                                                                             Energy meters plugs(6A6),                                     Stop-clocks(2A3)