Owner's Manual

ratio of transmittance at 931 nm to 653 nm is termed chlorophyll content index (CCI). A CCI measurement near
one indicates similar transmittance of red and NIR radiation, thus little to no chlorophyll in the leaf sample. A CCI
measurement greater than one indicates less transmittance of red radiation relative to near infrared radiation (for
example, see CCI value calculated from leaf transmittance spectrum in graph above), with larger ratios indicating
more chlorophyll.
The MC-100 chlorophyll concentration meter is unique in that it converts CCI, a relative measure of chlorophyll
content, to an estimate of actual chlorophyll concentration. There is a non-linear relationship between CCI and
chlorophyll concentration, and the relationship is different for different plant species (see relationship for three
different crop species in figure below). The MC-100 includes equations with species-specific coefficients for twe-
nty-two different species (see table below), an equation with generic coefficients derived from data for all twenty-
two species, and an equation to convert CCI to SPAD units (SPAD is the output from a similar chlorophyll meter
manufactured by Minolta). As custom coefficients for additional species are generated, they can be added to the
database in the meter by Apogee.