The paper adopts the COD constant temperature heating method to resolve water samples,conducts the CODCr parallel determination of two standard solutions, which is.

The precision and accurycy of the boiling water bath heating method were as the same as the oil bath heating metho.

Firstly analysis was made on the problems and reasons which were easily taken place when the bottling machine was operated at low temperature, and on this basis, constant temperature heating solution was raised.

When reaching the set temperature,the pressure cooker is in the state of intermittent or constant temperature heating so as to guarantee of safety of the pressure cooker and save electricity.

Based on the idea that the air-conditioner should set and control the radiating rate of the skin directly in a comfortable temperature,the constant-temperature heating wires,which is adjust to animal heat,controlled by heating wires constant-temperature circuits is introduced as intelligent sensor for air-conditioner,instead of traditional temperature sensor adopted by air-conditioner.