Page 5 Model 407445 Version 2.2 February 2004
RS-232 Serial PC Interface
This instrument includes a built-in RS-232 serial data port. This interface is intended for
use with the Extech Data Acquisition Software (PN 407001). For more information, contact
Extech or refer to the manual accompanying the 407001 software package.
Battery Replacement
1. The low battery indicator (LBT) appears on the left corner of the display when the
battery requires replacement. Reliable readings can be obtained for several hours after
the first appearance of the low battery indicator.
2. To replace the battery:
a) Remove the rubber jacket that encases the meter.
b) Open the rear battery compartment using a small coin or screwdriver.
c) Replace the 9V battery and re-assemble the meter.
