The following instructions about inserting and removing Safe‑Drive are written for Safe‑Drive generation 2.1. If you downloaded the instructions online or ordered a manual as a spare part, it is possible that your Safe‑Drive system is of different generation and a different set of instructions is needed. Vaisala strongly recommends upgrading the system to generation 2.1, for more information see https://www.vaisala.com/en/safe-drive-refractometer-pr-23-sd-manuals-safety-instructions-and-safety-videos.
The first place to look for the generation information is the retractor handle. If your retractor is generation 2, the handle has the code G2. If your retractor is generation 2.1, the handle has code G2.1. The difference between the generations is visible also when looking at the retractor and the isolation valve. For more information, see the following figure.