An opaque disk, typically white, used to gauge the transparency of water by measuring the depth ( Secchi depth) at which the disk ceases to be visible from the surface.
More example sentences
- Overall difference between species in use of Secchi depths varied by habitat type.
- Mean Secchi depths tended to be higher in 1996 than in 1997, but these differences also were not statistically significant.
- Temperature (in degrees Celsius) was measured at the surface and close to the bottom, and the Secchi depth was determined.
early 20th century: named after Angelo Secchi (1818–78), Italian astronomer.
Definition of Secchi disc in:
- The British & World English dictionary