Automatic temperature control technique for a Clinical Water Bath

The following paper is aimed at designing of a clinical water bath with an automated temperature control system. A temperature controller that maintains temperature of water at predefined value is attached to water bath which is a container. It is applied for incubation in microbiology or pathology laboratories. It is often observed that most of the water baths are manually controlled. Hence there seems need for automated temperature control. An automation is also done by using thermostat which is cheaper but the control band of thermostat is considerably wide, hence the variation of temperature about the predefined value is more. The proposed methodology eliminates wide variation of temperature about the pre-set value by controlling the amount of power input to the heater. Various temperature sensors were tested and LM 35 is used amongst them and the power input for heater is controlled in three bands namely 10 %, 50%, 100%. The task is done using microcontroller ATmega 16.