ZDST-2121 ‰Salt/Temp Digital Tester （2 in 1）
Range :     0‰ - 100‰ ( ‰PPt );   0-90°C (32-194 °F)
Resolution:  0.1‰ ;  0.1°C / 0.2°F
Accuracy(23±5°C):   0‰ - 9‰ (± 1‰); 10‰ - 19‰(± 2‰); 20‰ - 29‰ (± 3‰)
30‰ - 49‰ (± 5‰);  50‰ - 79‰ (± 10-15‰);  80‰ - 100‰ (± 15‰-20‰)
Operating Temp:  5 - 45°C ( ATC ) / 41 °F - 113°F ( ATC )
Calibration:   One point 35‰ Salt calibration buffer solution ( 3.5g NaCl/100mL pure water / 53 Salinity mS )
Power supply:        DC 4 X 1.5V ( LR44 or AG13 )
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).