PCE-TUM 20 Water Analysis Meter 0 ... 1000 NTU turbidity measuring range / Infrared LED light source / Calibration standards included. The PCE-TUM 20 water analysis meter is a handy turbidity measuring device equipped with a large LCD screen and user-friendly keyboard. This portable turbidity meter features two automatically switching measuring ranges between 0 ... 50 NTU and 50 ... 1000 NTU for increased accuracy. Using the included calibration standards 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.