A method of determining viability of pollen may evaluate the optical density of grains of pollen and compare the optical density to an optical density threshold.

The systems and methods detect the optical density of the plasma constituent and generate a first output indicative of the optical density.

A method for determining optical density is disclosed.

The optical density (OD) of the solution is measured at 565 nm.

The holographic image (109) is coated with a metal layer (111) of low optical density, while the covert image is produced by a metal layer (105) of high optical density disposed away from an observer relative to the holographic image.

An optical monitor (98) detects the optical density of the plasma constituent and generates a first output indicative of the optical density.

Subtract the optical density of the blank test solution from that of the sample solution (= corrected optical density).

From the specific optical density

Measure the optical density as indicated in 5.2.

Next, an optical property, such as optical density, is measured for each image region.

The optical density of the markings is 1.5 or more.

Soil increases the optical density of euro banknotes.

with an optical density of each aluminium layer of not more than 3.0

with an optical density of each aluminium layer of not more than 3.0

Optical density gradient is calculated as a function of the difference in optical density between a first and second region on the one or more images.

Development of coloration and measurement of optical density

E corrected optical density, determined as indicated in 5.2

Determine the optical density as indicated in 5.2 for free gossypol.

wavelength used for spectrophotometric reading of Neutral Red optical density

An optical layer comprises a connected glass panel (20) in which areas of high optical density are optical conductors.