1）Accurate measurement depends on careful calibration. Follow the instructions above closely. Note: Shifts in ambient room temperature of the prism prior to measurement. The prism and sample must be at the same temperature for accurate results.

2） Do not expose the instrument to damp working conditions, and do not immerse the instrument in water. If the instrument becomes foggy, water has entered the body. Call a qualified service technician or contact your dealer.

3） Do not measure abrasive or corrosive chemicals with this instrument. They can damage the prism's coating.

4） Clean the instrument between each measurement using a soft, damp cloth. Failure to clean the prism on a regular basis will lead to inaccurate results and damage to the prism's coating.

5） This is an optical instrument. It requires careful handling and storage. Failure to do so can result in damage to the optical components and its basic structure. With care, this instrument will provide years of reliable service.