Analytical process instrument - with zero and steepness adjustment by permanent magnets through non-magnetic wall

摘要

An instrument for direct readings of process parameters such as pH-values, redox potentials, dissolved oxygen and others is housed in a casing, made of non-magnetic material. It is equipped with adjusting devices both for the zero setting and for the steepness of its inherent characteristic. Both internal adjustment spindles are fitted with a fourpole permanent magnet which lies flush against the front wall of the instrument. To operate them, the service man rests another similar permanent magnet on the front and turns it. This saves having to open the instrument or to seal the spindles. Only authorised persons can carry out the adjustments.