For these reasons the type of data presented here can give no information on the effects of t in isolation. Another related factor is the greater reliability of HTC values for last effect due to the high t values (between 15 and 35°C here). In control the great majority of t values for earlier effects are below 10 °C. an error of 1°C would thus have a significant influence on the calculated HTC value, and it is not easy to achieve this accuracy under typical sugar factory conditions of varying temperature due to changes in juice feed and vapour bleed rates, and steam pressure.