PASPORT Colorimeter Sensor - PS-2121

Move to Wireless!

Recommended Alternative — The Wireless Colorimeter and Turbidity Sensor can perform all of the functions of the PASPORT Colorimeter Sensor at a lower price while also doubling as a turbidimeter. Best of all, it connects directly* to your computers, tablets, smartphones and Chromebooks without the need for an interface and with no cables to get in the way.

*Devices without native Bluetooth® Smart connectivity will require a low cost USB adapter - see the product page for details.

If you're looking for a Colorimeter for Water Quality Studies, please see the PASPORT Water Quality Colorimeter (PS-2179)



  • 5 Borosilicate glass cuvettes
  • Molded plastic storage case for sensor and cuvettes
  • Sensor Extension Cable
  • Overview

    Our PASPORT Colorimeter records all 4 wavelengths simultaneously--no need to guess at wavelength to get a quality measurement. Digital circuitry handles the calculations, calibrations and adjustments – all you have to do is collect data. Simultaneously reports both absorbance and transmittance. Black, opaque housing eliminates ambient light to assure data accuracy.
    Great for Beer's law experiments, absorbance vs. concentrations, and reaction rates.

    • Auto calibration – insert a cuvette of clear water, press one button and calibration for all wavelengths is done.
    • Samples 5 times a second - making rates of reaction experiments a reality.


    Typical Applications

    • Study absorbance vs. concentration
    • Determine the concentration of an unknown solution (Beer's Law experiments)
    • Measure reaction rates

    Special Features

    • Stabilized light source for consistent readings
    • Simultaneously reports both transmittance and absorbance
    • Borosilicate cuvettes last longer than plastic and have greater optical clarity


    • 0-100% transmittance
    • ±0.5% transmittance
    • 0.1% transmittance
    • 468 nm (blue)
    • 565 nm (green)
    • 610 nm (orange)
    • 660 nm (red)
    Maximum sampling rate
    • 5 samples/s (default is 1 sample/s)
    Operating Temperature
    • 0° C to 40° C

    Additional Videos

    Buying Guide

    PASPORT Sensor Extension Cable
    PASPORT Sensor Extension Cable   PS-2500
    Replacement Cuvettes/Cap
    Replacement Parts
    Replacement Cuvettes/Cap   PS-2509

    Interface Required

    To use this product you need a PASCO interface. 

    New to probeware or have questions about  sensors or interfaces? Contact Teacher and Technical Support.  We're here to help!

    Software Required

    SPARKvue software or PASCO Capstone software may be used. PASCO Capstone is available for Mac and Windows. SPARKvue is available for Mac, Windows, iOS, Android and Chromebooks.

    Learn more about Bluetooth Compatibility.