Fluke 1504 User Manual page 19

1504 Thermometer Readout
User's Guide
14
NOTE: The DC power option includes a low voltage indicator. The low
voltage indicator needs to be plugged into the instrument with the battery
option plugged in to the low voltage indicator. The low voltage indicator
light illuminates when the voltage drops below a safe operating range. The
instrument should not be used for measuring when the low voltage light is
illuminated. Recharge the battery to an acceptable level before taking
measurements.