Research is done on the measuring cell

light path and data acquisition system of a magnetomotive oxygen measuring instrument. Base on the magnetic performance of gas

the moment of rotation of a dumbbell is derived when it is in a nonuniform magnetic field. A design of the measuring cell is proposed

a rotary resistance for the dumbbell ball is implemented by a silver-coated erosion approach

and the techinque requirements are analyzed for the nonuniform gradient magnetic field. The light path and the CCD data acquisition system are introduced. To meet the requirements for instrumental scaling

temperature compensation and correction

five functional keys are set up

and their function are explained by list. The correction programme of the instrument and test data is given later on.Experiments results show that the precision of the instrument is above 0.2% at different temperature

the performance of temperature compensation

the precision and stability of the instrument satisfy the design requirements.