STM - W/O series of dual - purpose heaters are mainly used to heat up the mould and maintain its temperature, although they can be also used in other similar applications. High temperature water or oil return from the mould is cooled by indirect cooling and then sent to the pipe heaters via high - pressure pump for heating to a constant temperature. This unique design allows user to choose between water and oil as heat transfer medium. With our optimised design, the OMRON temperature controller can maintain an accuracy of ± 1º C.