Hanna Instruments HI 98703 - Manual (Page 7)

7
MEASUREMENT UNITS
Many methods were used to measure turbidity over the years. The Jackson Candle Turbidimeter was
used to measure turbidity as Jackson turbidity units (JTU). The Secchi Disk is commonly used to
measure turbidity in lakes and other deep waters (mg/L SiO
2
). Both methods are visual and are not
considered very accurate. To obtain more accurate readings a nephelometer should be used as a
turbidity reading instrument.
The
HI 98703 turbidimeter reports the measurements only in NTU (Nephelometric Turbidity
Units). NTU units are equal to FTU units (Formazine Turbidity Units). The conversion table
between these measurement units is shown bellow:
U T J U T F / U T N O i S
2
) L / g m (
U T J 1 9 1 0 5 . 2
U T F / U T N 3 5 0 . 0 1 3 1 . 0
O i S
2
) L / g m ( 4 . 0 5 . 7 1