The intrinsically safe process refractometer consists of the following:
- A modified refractometer sensor PR‑23‑…‑IA/‑IF/‑CI/‑JI/‑RI
- An indicating transmitter STR with single sensor connectivity
- IS isolator and cabling between the refractometer sensor and the transmitter
The equipment is intrinsically safe only if all mounting instructions in Intrinsically safe mounting are followed. If the instrument has been in any way damaged during transportation, return it to your nearest Vaisala service point for checkup before installation. Never install a damaged instrument into the process line.
The intrinsically safe sensor PR‑23‑…‑IA/‑IF/‑CI/‑JI/‑RI is identified by the nameplate, see the following figure. The Indicating transmitter is of model STR, for single sensor connection.
An intrinsically safe sensor has a different processor card and a different terminator card than a standard sensor, other parts are as in standard sensor (see earlier in this chapter for full parts list).
| WARNING Do not replace any part of an intrinsically safe sensor with a standard sensor part. |
| WARNING If the sensor cover is made of aluminum, the refractometer sensor can cause ignition if it hits other metal parts during the installation. An aluminum sensor cover must have a sticker warning about this possibility. |
| WARNING The refractometer models PR‑23‑M, PR‑23‑MS and PR‑23‑W contain parts made of PTFE in sensor heads. These parts are subject to electrostatic hazard. The refractometer models PR‑23‑M, PR‑23‑MS and PR‑23‑W shall only be used for measuring liquids with high conductivity (> 10000 pS/m) in the presence of hazardous atmospheres. |
| WARNING The painted surface of the enclosure of PR‑23‑MS refractometer is subject to electrostatic hazard and therefore the cleaning shall be done only with a damp cloth in the presence of hazardous atmospheres. |