KS-12 Digital Salinity refractometer

Digital Salinity refractometer KS-12 Range: 0% - 10% Salt; 0-90C (32-194 F) Resolution: 0.01%; 0.1C / 0.2F Accuracy (23±5C): 0%-2.9% (± 0.1-0.3%); 3.0%-4.9% (± 0.3-0.5%); 5.0% - 10% (± 0.5-1.0%) Operating Temperature: 5 - 45C (ATC) Calibration One point: 3.5% Salt calibration buffer solution (3.5g KCL/100mL pure water / 53 Salinity mS) Power supply DC 4 x 1.5V ( LR44 ) Features: Automatic switch-off function: After 8-10 minutes without pushing buttons, the meter will be switched off automatic. Data holding (for 8-10 minutes).