Kemtrak Color and Concentration Analyzers

Process color and concentration measurements of liquids are a vital part of many operations where precise process control and high product quality standards are required. Typical application of color analyzers are:

  • Product color control for QA/QC
  • Chemical concentration
  • Filtration bed monitoring
  • Ion exchange column monitoring
  • Leak detection
  • Contaminant detection
  • Dilution and dosing control
  • Interface detection


The Kemtrak DCP007 process photometer is designed to accurately measure color/concentration even in turbid or hazy flow streams. The unique referencing system used by Kemtrak analyzers removes the effects of solids suspended in the flowing stream to give a “true color” measurement. The DCP007 uniquely provides outputs for both color/concentration and solids/turbidity from the same unit – a true multifunction instrument.


Addition and dosing of chemicals such as ClO2 are easily controlled using a Kemtrak analyzer as the uncertainty of measurement surrounding many other measurement methods is removed by the rock-steady performance of the unit in line.

Is Kemtrak Right for Your Application?

Let Kemtrak give you a solution – download an application data sheet, fill in your process specifications and send it to us. We’ll come back to you with a configuration that will suit your needs.

Typical Color and Concentration Scale Applications

Typical Color Scales that can be measured using the DCP007 process Analyzer are:


Color Scales/StandardsScopeRange
Saybolt Color:
ASTM D 6045
ASTM D 156
J1S K258
Light colored petroleum products, including aviation fuels, gasoline, kerosene, naphtha, white mineral oils, hydrocarbon solvents and petroleum waxes.
Download Data Sheet
-16 (darkest) to +30 (lightest)
ASTM Color:
ASTM D 6045
ASTM D 1500
Also JIS K2580 - IP 196 - NFT 60104 - ISO 2049 -DIN 51578
Petroleum products, including lubricating oils, heating oils and diesel fuel oils
0.5 - 8 units
APHA/Hazen Color
ASTM D 1209
Hazen (APHA) is a measure of yellowness originally designed to evaluate the color of near-colorless water by visual comparison with a platinum-cobalt (PtCo) stock solution.
Download Data Sheet
0 – 500ppm
ICUMSA Color Index
Color scoring of filtered sugar solutions at a known concentration (Brix value).
Download Data Sheet
100 – 13000 units
EBC (European Brewing Convention
SRM/°L (Standard Reference Method/degrees Lovibond)
The °L scale is a visual standard that was used before online measurement means were available. SRM color can be measured online and approximates °L. The online EBC color scale was developed by the Institute of Brewing and the European Brewing Convention. All are recognized methods for color grading beers, malts and caramel solutions in the beverage industry.EBC: 4 – 79 units
SRM/°L: 2 – 40 units
Iodine Color
DIN 6162
Colors ranging from yellow to brown are described against specified dilutions of an iodine solution. The iodine scale is used for measuring the color of solvents, plasticizers, resins, oils and fatty acids.1-500 units
Spectral data
(400 - 700 nm)
For concentration measurements online, spectral data at a fixed wavelength can be used. Correlating an online measurement to laboratory measurements provides a reliable “calibrated eyeball” that can be used as a monitoring/control element in a flowing processes. Any process that has a consistent color signature can be measured using an online color system.0-100%
0 – 5A
Custom scales

Traceable Validation Accessory

The optional Kemtrak NIST-traceable validation filter holder is supplied either fitted to the optical flow cell or as a standalone accessory in the optical fiber chain. It permits the use of either NIST traceable reference standards or liquid samples to quickly check instrument performance on a regular basis to ensure the photometer is operating within satisfactory parameters without having to remove the flow cell from the process line.

The Kemtrak NIST-traceable validation filter holder is designed to use industry standard 10mm cuvette style NIST-traceable absorbance filters, the same type as used on many standard laboratory spectrophotometers.

Benefits of using a Kemtrak NIST-traceable validation filter holder include:

  • Fast verification of measurement accuracy
  • Industry standard 10mm cuvette size
  • Same set of standard NIST filters as used in the laboratory
  • Cross validation between laboratory spectrophotometer and Kemtrak in-line industrial process photometers
  • Liquid samples can be measured
  • Recognized by international quality systems such as GLP, ISO 9000 and ISO/IEC 17025

Technology Overview

The Kemtrak DCP007 photometer measures at two wavelengths. A primary “absorbing” wavelength is used to measure the concentration of the chemical being monitored while a “non absorbing” reference wavelength is used to compensate for turbidity, air bubbles and/or fouling.

The Kemtrak DCP007 photometer uses precision fiber optics to shine a precisely focused monochromatic light through the process medium and back to a photo-detector.

The attenuation of the transmitted light beam caused by absorbing substances in the process medium is mathematically described by the Beer-Lambert law.

Applying the Beer-Lambert law (below), the concentration of the sample can be calculated.

A = ε l c


A = absorbance (= – log transmittance)

ε = molar absorptivity coefficient

L = optical path length

C = concentration of absorbing species