Sofamel BTL-600 Manuel D'instructions page 31

6. Meter instructions
Red meter probe
Light
Non-contact voltage sensing area
Non-contact voltage indicator
Rotary switch
Display
Key
Data holding
Range selection
Backlight and illumination
Press and hold for more than 2 seconds to turn on the backlight
and illumination lights.
Press and hold for more than 2 seconds again to turn it off.
Function selection
Black probe
31