Wireless Colorimeter and Turbidity

Product Code: PS-3215


The Wireless Colorimeter simultaneously measures the absorbance and transmittance of six different wavelengths. The sensor can be used to study Beer’s Law (absorbance vs. concentration), enzyme activity, photosynthesis, and the rates of chemical reactions (absorbance vs. time). After a simple calibration, students can quickly begin viewing live measurements as they materialize across the visible spectrum at 650 nm (red), 600 nm (orange), 570 nm (yellow), 550 nm (green), 500 nm (blue), and 450 nm (violet).

This sensor also functions as a high-quality turbidimeter for water quality analysis. Rather than simply measuring transmitted light, the Wireless Colorimeter and Turbidity Sensor measures light scattered at a 90 degree angle from the sample, resulting in accurate and repeatable measurements. Additionally, the internal housing for the cuvette is opaque, which limits ambient light interference to preserve accuracy.

How It Works

Absorbance and Transmittance: Light from a broad band white LED light source passes through the solution onto a CCD array which detects the light and analyzes it. Parts of the array are covered by narrow band filters which allow 6 of the visible wavelengths (Violet, blue, green, yellow, orange, and red) through to the detector. The absorption can be plotted as a function of concentrations to form Beer’s law plots or absorption over time graphed for kinetics investigations.  A collimated light source directed perpendicular to the sensor can be used for turbidity.

Important Note: Solutions used within this spectrometer should be compatible with polystyrene (cuvette material) and ABS (spectrometer housing material). Use a glass cuvette or 12mm test tube for solutions with strong organic solvents like acetone, which will damage the plastic cuvettes.

Lab Activities & Experiments

Visit PASCO’s Experiment Library to view more activities.

Typical Applications

  • Beer’s Law (absorbance vs. concentration)
  • Measuring reaction rates using absorbance vs. time
  • Turbidity testing and colorimetric analysis in the field
  • Determining the concentration of an unknown solution
  • Comparing the turbidity of water samples


  • Stabilized light source for consistent readings
  • Measures six different wavelengths simultaneously
  • PASCO software displays the absorbance & transmittance at each wavelength in the appropriate color
  • Quick and easy calibration
  • Functions as both a colorimeter and turbidimeter
  • Wireless design enables data collection in the field


  • Colorimeter/Turbidimeter
  • USB charging cable
  • 6 colorimetry cuvettes (2 clear sides and two ribbed sides)
  • 4 turbidity cuvettes (4 clear sides)
  • 2 cuvette racks
  • Calibration cuvette and 100 NTU solution


Color detection/peak wavelengths
  • 650 nm (red)
  • 600 nm (orange)
  • 570 nm (yellow)
  • 550 nm (green)
  • 500 nm (blue)
  • 450 nm (violet)
Colorimeter Detector Ranges
  • ±25 nm from peak
Colorimeter Absorbance
  • 0-3 Abs units; useful range (0.05-1.5 Abs)
  • 0 – 100%
Colorimeter Precision
  • ± 0.03 Absorbance units
Turbidity Range
  • 0 – 400 NTU
Turbidity Accuracy
  • ± 5% NTU

Supporting Documents

Wireless Colorimeter and Turbidity Sensor Manual

StablCal Standard, 100 NTU – Safety Data Sheet