A reasonable indication of Pour Point can be made without expensive equipment.
Info Centre >> Fuel and Lube Oil Technical Manual >> 2. Fuel Oil - Characteristics >> 2.5 Pour Point
Fuel Oil Pour Point
The pour point is the lowest temperature at which a fuel can be handled without excessive amounts of wax crystals forming out of solution. If a fuel is below the pour point, wax will begin to separate out and this will block filters. Also, the wax will build up on tank bottoms and on heating coils. When heat is reapplied difficulties may be experienced in getting the wax to re-dissolve because of its insulating nature. In extreme cases, manual cleaning of tanks may be necessary.
Although some diesel oil is sometimes delivered as a clean product, for the purpose of wax indication it is considered as 'black'. This is because it may be delivered through the same transfer lines as residual fuels and can thus be mixed with considerable amounts of wax-laden residual fuel.