This instrument is a panel instrument for on-line monitoring of industrial process conuctivity. Range switch over and constant check can both be freely set and anjusted through the operation component on the rear panel; unique signal collecting and proces sing technology and apecial think film circult are adopted to make measurement accurate and operation stable; there are also other features such as linearized data, automatic temperature compens ation, not subject to the length change of cable and maintenance-free. It's an ideal auxiliary instrument of various types of small pure wather equipment.