The indicating transmitter DTR is only compatible with the PR‑23 refractometer range. One or two PR‑23 refractometer sensors can be connected to the DTR.
For intrinsically safe installations (see Intrinsically safe refractometers PR‑23‑…‑IA, PR‑23‑…‑IF, PR‑23‑…‑CI, PR‑23‑…‑JI and PR‑23‑…‑RI) there is a single-sensor version of the transmitter (STR). The information given in this chapter applies to STR as well, unless otherwise indicated.