These specific gravity hydrometers are marked with reference norms, calibration temperature, surface tension, individual and serial numbers.

• Reading below the meniscus
• Calibration temperature of 15 °C
• Benchmark on the stem to show any movement of the scale

Calibrated according to the following tensions:
0,600 to 1,000 Sp.Gr.= 16 to 35 mN/m (low tension)
1,000 to 1,300 Sp.Gr.= 55 mN/m (medium tension)