The Vaisala K-PATENTS® In-line Refractometer is an instrument for measuring liquid concentration in the process line. The measurement is based on the refraction of light in the process medium, an accurate and safe way of measuring liquid concentration.
The in-line refractometer sensor measures the refractive index nD and the temperature of the process medium, see Figure 1. This information is sent through the interconnecting cable to the indicating transmitter, see Figure 2. The indicating transmitter DTR calculates the concentration of the process liquid based on the refractive index and temperature, taking pre-defined process conditions into account. The output of the DTR is a 4 … 20 mA DC output signal proportional to process solution concentration. Process data can also be downloaded to a computer via an Ethernet cable. The labels on the refractometer show the technical model specifications of the refractometer, see Figure 3.
