Optical sensor for the measurement of low color
The sensor is used to measure color concentrations in the low measuring range of the visible electromagnetic spectrum.
- Color scale measurement: APHA/Hazen, potassium permanganate in water
- Measurement of color concentration
- Outgoing goods inspection/purity monitoring
- Color assurance
- Discoloration control
- Distillation monitoring
Cost-effective, time-efficient verification (liquid-free)
FM and ATEX approved lamps for applications in the hazardous area
Broad variety of window materials and seals for resistance to a wide range of process media
Optional air purge ports to prevent the formation of condensate on the optical windows
- As slightest color changes are detected, production quality is guaranteed
- Measuring range up to 2.5 AU or 50 OD (depending on optical path length)
- Can be configured to measure color concentration at discrete wavelengths in the visible regionregion
- Outstanding filter properties for highest linearity
- Direct concurrence with laboratory values
- Integrated reference detector for the compensation of particles, bubbles and lamp aging
- Incandescent lamp for long service life and stable measured values
The measuring principle is based on the Lambert-Beer law.
There is a linear dependency between the absorption of light and the concentration of the absorbing
A = -logA m = ε . c . OPL
A ... absorption, A m ... absorption measured by detector
ε ... Extinction coefficient
c ... Concentration
OPL ... Optical path length
A light source emits radiation through the medium and the incident radiation is measured on the
A beam splitter splits the light into two beams. One beam is used for measuring while the other acts
as a reference to compensate for particles, bubbles and lamp aging.
Once the light has passed through a filter for wavelength selection, the intensity of the light is
determined by a photodiode and converted to a photocurrent.
The subsequent conversion to absorbance units (AU, OD) is performed in the associated transmitter.