Brand: WTW
Features:
- Tungsten lamp according to US EPA battery operation
- Portable use for waste-water, surface water and ground water applications
- Single instrument in case with 4 AAA alkaline batteries
- Calibration set (0.02 - 10.0 - 1000 NTU), 2 empty cuvettes and cleaning tissues
Thomas Scientific
Details: Nephelometric or transmittance measuring-the nephelometric measurement at 90° scattered light is advantageous for lower turbidity, whereas the transmission measurement at 180° is beneficial for medium to high turbidity values: With increasing turbidity, restray and scattering effects between particles are growing bigger. The reduction of light intensity in this case leads to a more accurate result than a 90° nephelometric measurement. Therefore, lab meters for high values are equipped with several measuring options: ratio modes calculate the final result from different measured angles. For ratiometric measurements, there is no specific standard method to be followed; rather, procedures are established by the application or industry. White light has a higher sensitivity for small particles, however, the inherent coloration of the solution has a stronger disturbing effect in this case. The IR measurement is required by DIN ISO, the white light measuring by US EPA.
