PCE-TUM 20 Photometer
0 ... 1000 NTU turbidity measuring range / Infrared LED light source / Calibration references included

PCE-TUM 20 is a portable handheld photometer or turbidimeter for water quality analysis. This turbidity measuring device is equipped with a large LCD screen and user-friendly keyboard. The turbidity meter features two automatically switching measuring ranges between 0 ... 50 NTU and 50 ... 1000 NTU for increased accuracy. Using the included calibration references of 0 NTU and 100 NTU, the meter can be adjusted at any time. (Note: NTU stands for Nephelometric Turbidity Unit.)

Inside the meter, there is an infrared LED light source with a wavelength of 850 nm. A photodiode positioned in a 90° angle to the measuring ray absorbs the light reflected by the particles in the dissolution. Diffused light or Nephelometric measuring methods are used for the lower measuring range. For the higher measuring range, an additional photodiode is positioned at the opposite side; therefore, measurement is performed via the transmitted light method.