Optical check disc for cobas b 101 The optical check disc has been designed to test the optical functions of the Roche cobas b 101 IVD blood analyser. If the test passes, the optical functions of the instrument are considered to work normally. When to run the optical check The optical check test should be performed in the following circumstances: Before the instrument is used for patient testing for the first time When the test interval has been exceeded If a message for optical check lockout is displayed If an error message concerning the optical system is displayed If you want to check the optical functionality of the device After impact on the instrument (e.g. after accidentally knocking the instrument) Each time the instrument is moved After the instrument has been transported from one location to another, before patient testing is initiated in the new location