Principles of Methodologies
Principles of Rate Nephelometry
Theory of Operations
IMMAGE 800 Operations Manual A11403
Page 3-2
September 2016
Theory of Operations
Principles of Methodologies
Principles of Rate Nephelometry
The rate nephelometer measures the increase in the intensity of light scattered by
particles suspended in a cuvette. The light source for the rate nephelometer is a 670
nm laser. The detector is placed at a 90° angle from the laser beam to measure light
scatter, as shown in Figure 3.1.
Principles of Rate Turbidimetry
The rate turbidimeter measures the decrease in the intensity of light as it passes
through a solution of light scattering particles in a cuvette. The light source for the
rate turbidimeter is an light emitting diode (LED) at a wavelength of 940 nm.
Turbidimetric measurements are made at 0° from the incident beam as shown in
Figure 3.1.
Figure 3.1
IMMAGE 800 Rate Nephelometer and Rate Turbidimeter Basic
Components
1. LED light source (turbidimetric)
2. Laser light source (nephelometric)
3. Focus lens
4. Beam splitter
5. Reaction cuvette
6. Nephelometric detector
(90° angle to incident laser beam)
7. Laser light bounces into light trap
8. Turbidimetric detector (0° angle to the
incident LED beam)