A look at the ways in which domestic appliances are tested for safety and durability before they are sold.
M/S of a laboratory where household appliances are tested being for faults. On a table are two electric fires - one with a safety guard, one without. Two scientists dressed in white coats are holding with metal tongs scraps of fabric in front of each fire. The scrap held in front of the unguarded fire burns rapidly while the other remains in tact. C/U of the slightly scorched scrap being held in front of the guarded fire, before being placed onto the table. The narrator explains these experiments are part of the work of the Electrical Development Association.
High angle M/S of another area of the laboratory. On a grey felt bed, a scientist is unfolding the insulation from an electric blanket. Two sheets of foil and placed on either side of the insulation before a grey felt cover is rolled over it. Two metal weights are placed on top of this. C/U of one of the scientists operating the machine which is about to shoot one thousand volts through the foil for sixty seconds - "any shorting between the charged foil and the wires inside the blanket and you'd jump out of bed pretty quickly". C/U of the voltage dial on the machine. Tilt up to a stop clock on top of the machine.
Top shot of the inside of an upside down washing machine and the hands of a scientist fitting a thermocouple to it. This test is less to do with safety and more to do with performance - many manufacturers submit products to the association before they are put on the market. M/S of two scientists turning the machine the right way up and connecting it to the power. The narrator jokes that "scientists here tackle household chores in a manner that would do credit to their wives". M/S of a scientist checking the machine that measures the temperature. After fiddling with some dials, the scientist adds some detergent to the washing machine. Another scientist walks in, carrying a pile of dirty dishcloths which are loaded into the machine. The purpose of this experiment "couldn't be simpler" - it is to test the claim that so many pounds of washing can be completed in so many minutes. Top shot of the washing machine in action. M/S of one of the scientists noting down information from the various bits of equipment attached to the washing machine. Top shot of more dirty dishcloths being added to the washing machine. M/S of the scientist keeping a constant check on the temperature in different parts of the machine. C/U of one of the machines recording the temperature.
M/S of a scientist carrying out "a test concerned with the resistance of plastics as insulators under rough conditions". C/U of an electric current being passed through two electrodes held in a clamp above a sheet of plastic; the solution is dropped onto the plastic to test its resistance. Smoke rises as the plastic breaks down.