> The tog is a measure of thermal insulance of a unit area, also known as thermal resistance. It is commonly used in the textile industry and often seen quoted for duvets and carpet underlay.
> Developed at The Shirley Institute in Manchester, as an alternative to the SI unit of m2K/W.
> Basic unit of Tog (insulation coefficient) is the RSI, (1m2⋅K/W). 1 tog = 0.1 RSI: Thermal resistance in togs is equal to 10x the temperature difference (in °C) between 2 surfaces of a material when the flow of heat is equal to one watt per m2. Tog is measured from the difference in temperature between a heated metal plate beneath a fabric and the air temperature above the fabric. This is a much more objective measure than Comfort Ratings, as commonly used for sleeping bags and can be applied to a wider variety of sleep systems. It is also possible to provide a Wet & Dry Tog value, useful when describing use in typical UK conditions.