The TurBiScat 2 Ex measures turbidity in liquids. The transmitted light and the scattered light are measured at 90° and 25°. In this way, the proportions of smaller or larger particles become visible and colour and window contamination are compensated for. Optionally, there is the possibility of an additional colour measurement at 430 nm. The calibration is checked with a solid reference. The TurBiScat 2 Ex is conceived and designed for applications in explosion-protected areas.