Dwyer GDL - Manual (Page 24)

DwyerLog User’s Guide Versin 1.2x 24/25
When in the graph screen, you can use the Display - and Display + buttons to shift the graph left and right,
respectively. Pressing and holding the Start button, while in the graph screen, returns the graph view to the last
sample taken.
When the logger is logging, the graph display is automatically updated as new samples are logged.
GDL Buttons
The GDL has five buttons as shown below.
• Units: Use this button to change the displayed units between °F and °C.
• View: Use this button to change the displayed screen.
• Start: If the logger has been setup to start on button press, press and hold the Start button to begin
logging. In the Graph screen, pressing and holding this button returns the view to the last sample logged.
• Display +: Use this button to increase the screen contrast when in Sample and Summary screens. When in
the Graph screen this button shifts the graph to the right.
• Display -: Use this button to decrease the screen contrast when in Sample and Summary screens. When in
the Graph screen this button shifts the graph to the left.
Replacing the GDL Battery
The GDL uses three AA type alkaline or lithium batteries. Using rechargeable Ni-MH batteries is not
recommended. The battery level of the GDL is shown on the screen, or can be checked using the DwyerLog
software, by opening the Logger Status window. It is suggested that the battery is replaced when the battery level
reaches 1 bar on the display, or in the yellow zone in the DwyerLog software. When the battery indicator is empty,
or reaches red in the DwyerLog software, it is imperative that the battery is replaced as soon as possible. When the
battery level is too low, the logger will stop logging automatically, resulting in data not being recorded. The
DwyerLog software will give you a warning if you try to start a logging session while the battery is low.
To conserve battery power, the GDL will shutdown automatically, when not logging, after about one hour of
operation. To turn the logger back On, just press any button. The logger can run while logging continuously for one
year on a single set of three AA alkaline batteries.
To replace the batteries follow these steps:
1. Disconnect the logger from the USB cable. Do not replace the battery while the USB cable is connected!
2. Using a screwdriver, remove the 4 screws in the back of the logger.
3. Carefully remove the back case. Be very careful not to pull on the battery wires.
4. Remove the three used AA batteries.
5. Press and hold any logger button for about 2 seconds. This step removes any extraneous charge from the
logger system. This step is very important. The logger may not operate correctly if this step is not
performed.
6. Insert three new AA batteries into the battery holder. Make sure that the + indicator on the battery matches
the + indicator on the battery case.
7. When the batteries is replaced correctly, the logger should start up automatically and show the Sample
screen.