The shutter status safety indicators on the measuring heads provide a second, 360-degree 
indicator set if the user is working inside the scanner frame and cannot see the endbell 
user panel status lights. 
If the indicators are glowing green, the shutters are closed and it is safe approach the 
heads. 
If the indicators are glowing red, a shutter is open and the measuring heads should not be 
approached (see Figure 48). 
 
Fig. 48.   Shutter Status Indicators on Head 
2.3.3.2  Sensor Key Lock 
Description: 
Sensors associated with safety hazards feature a lockout keyswitch on the user panel. A 
separate key is provided for each sensor hazard type, nuclear and laser. 
When the keyswitch is activated, a yellow indicator is lit to the right of the key. Sensors 
associated with this hazard type can be enabled for operation by pressing the 
corresponding sensor icon/button. An enabled sensor will show a lit icon (see Figure 49). 
 
Fig. 49.   Sensor Key Lock