Color, Concentration, Turbidity



The Kemtrak 007 analyzer platform allows the configuration of a wide range of state of the art industrial optical analyzers designed to accurately measure and report specific properties of liquids (and gases) inline and in real time. Based upon either absorbance, light scatter or fluorescence, Kemtrak photometers are widely deployed in the industry to measure process parameters such as color, concentration, turbidity, and solids concentration in many different applications.

Each unit consists of an advanced electronic unit with a light bench constructed using high-performance light source technology, rugged industrialized fiber optic cables and an inline flow cell or probes with wear resistant sapphire windows. The key to the outstanding performance of Kemtrak analyzers is that the output of the light source is kept extremely stable over long periods of time, essentially eliminating the drift seen on so many older design optical instruments where light output changes through aging. High reliability ensures that maintenance requirements are very low – the cost of ownership is one of the most attractive amongst inline optical instruments in the marketplace today – and while each instrument is carefully configured to suit each and every application, change to repurpose the instrument in the field is a quick and simple task.

Color and Concentration

The Kemtrak DCP007 is an easy to operate industrial fiber optic photometer designed to accurately measure the concentration and color of process samples. Measurements are real time and in-line.

A proprietary dual wavelength four channel measurement technique and advanced digital electronics design allows deep absorbance measurement to 5 AU. Automatic compensation for sample turbidity and/or fouling of the optical windows ensures trouble free operation.

Maintenance free measurement cells with sapphire windows have no electronics or moving parts making them suitable for hazardous area use.

» Kemtrak Color and Concentration Analyzers

NIR Analyzers

The Kemtrak DCP007-NIR analyzer is an advanced dual wavelength NIR photometer designed to accurately measure the concentration of process liquids and gases with near-infrared (NIR) absorbance between 800 and 2000 nm.

Examples of NIR measurements include moisture (water & trace water), ethanol, methanol, sodium hydroxide, ammonia and continuous fuel identification.

» Kemtrak NIR Analyzer

Suspended Solids

The Kemtrak NBP007 is a high resolution backscatter photometer that revolutionizes the measurement of high concentration suspended solids.

Traditional turbidity based optical measurement instruments lack resolution and stop working at approximately 1% suspended solids due to the extremely high optical density. This limitation is overcome with the NBP007 and for the first time the operator can monitor and have complete control over their process at any concentration.

» Kemtrak Suspended Solids

UV Absorbance

UV Absorbance for Sugar Color

The Kemtrak DCP007-UV process analyzer uses ultra-low power cold light LED’s at only the wavelength required for the analysis, exposing the sample to thousands of times less energy than traditional UV photometers. Traditional UV photometers use mercury vapor lamps that continuously expose the process stream to high intensity broad spectrum UV radiation and heat generated by the lamp.

Convenient zero dead-volume hygienic measurement cells contain no electronics or moving parts and are well suited for hazardous environments. NIST traceable validation filters are available to verify analyzer performance without process interruption.

» Kemtrak UV Analyzer

Fluorescence (Oil-in-Water)

A Kemtrak FL007 fluorometer is used to accurately monitor fluorescent substances. An advantage of this technique is extremely low concentrations can be detected – parts per billion can be achieved.

The Kemtrak FL007 analyzer uniquely utilizes both fluorescence and turbidity measurement using proprietary dual wavelength ratio measurement techniques for continuous monitoring in applications like trace oil and hydrocarbon contamination in water. The FL007 can be configured to monitor other fluorescing substances (such as Fluorescein) in line in real time for leak and marker detection.

» Kemtrak Fluorescence Analyzer


Kemtrak turbidimeters provide reliable online turbidity measurement for a whole range of applications throughout industry. With options to use either 90° side scatter, 180° attenuation or back scatter techniques, Kemtrak turbidity analyzers can measure from 0.01 NTU to 10000 NTU or more.

Inline flow cells are available from ½” to 4” with a variety of different process connections, pressure/temperature ratings and a variety of different wetted materials.

» Kemtrak Turbidimeter

Have an 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.

Need Support?

Need a manual or additional information on your Kemtrak Analyzer?



  • APHA / Platinum-Cobalt (Pt-Co) / Hazen color scale according to ASTM D 1209, BS5339:76 (1993), DIN 53409 and ISO 6271-1:2004(E)


APHA, Platinum-Cobalt (Pt-Co) and Hazen are different names for the same color scale.  The APHA color scale measures the “yellowness” of a liquid and is well suited for quality control and contamination detection. It is regularly used to evaluate pollution levels in wastewater and for drinking water quality control and regulation. The APHA scale can also be used to measure and control the concentration of iron in groundwater.


Originally a visual standard using standard glass slides to compare against process samples inside a stereoscopic viewer, APHA has evolved to being electronically measured with portable testers.  A further evolution has moved measurements online so APHA color can be monitored in real time using photometers.


Online instruments (such as the Kemtrak DCP007) use a measurement wavelength that is typically between 380 – 500nm depending upon the process color range to be monitored. Highly colored processes (> 500 APHA) require a short optical path-length (OPL) while lightly colored process streams (<100 APHA) require a long OPL. A reference wavelength of 650nm or 850nm is used to compensate for both turbidity in the process stream and window fouling over time. Optimum selection of wavelength and OPL is necessary for the best performance.

Water Color Scale APHA



  • Direct real time measurement of watercolor
  • High resolution measurement
  • Automatic cleaning
  • No maintenance

The Kemtrak DCP007 is an industrial UV-VIS-NIR photometer designed to accurately measure the color of liquids. Real-time measurement results are displayed in units of PCU (Pt-Co), Hazen or APHA. The Kemtrak DCP007 uses a high performance long life LED light source with robust industrial fiber optics to provide a measurement with very high precision. A proprietary dual wavelength four channel measurement technology allows accurate measurement of both highly colored and trace color levels. The primary “absorbing” UV-VIS wavelength accurately measures watercolor, while the second reference NIR wavelength, which is not influenced by the watercolor, compensates for turbidity and/or fouling of the optical windows.


Since optical fibers are used to transmit light to the measurement point and back, the measurement cell contains no electronics, moving parts or sources of heat. Standard measurement cells are manufactured in robust stainless steel and use sapphire windows to provide long and maintenance-free operation. Measurement drift caused by LED light source or filter aging is negligible and once set, instrument recalibration is not required.


Where calibration is required, the Kemtrak DCP007 employs a simple automated QuickCal one point and zero calibration method that is suitable for the vast majority of applications.  Resolution of the measurement varies depending upon the overall depth of color monitored, typically in the order of:


Measurement range

0-50± 0,01 PCU
0-100± 0,02PCU
0-500± 0,1 PCU
0-1000± 0,2 PCU
0-5000 ± 1 PCU



Kemtrak Stainless Steel Long Pass

Kemtrak stainless steel long pass (OPL = 100mm) G 1” (DN 25) pipe thread measurement cell with optional G 1/8” (DN 6) sapphire window cleaning nozzles.

The most common measurement flow cell for lightly colored applications such as drinking water is a long pass stainless steel “Z” path cell, shown here with optional windows cleaning nozzles. The cleaning sequence can be fully automated using the inbuilt DCP007 controller software.

Wastewater monitoring is typically higher colored samples and a shorter OPL measurement cell is required. A typical measurement cell for this application is a 1” NPT type cell as shown above left.

Kemtrak Tapered Pipe Thread

Kemtrak stainless steel NPT 1” tapered pipe thread
measurement cell with sapphire measurement window.