Before starting and deploying your datalogger, you can "Zero" it to current atmospheric pressure. This will ensure that it is reading 0 in air for the level reading.
Note:
To check your datalogger's readings in air, use the Real Time View function. See Section 7.
![Datalogger Zero will zero the water level reading for the LevelVent Water Level Datalogger datalogger zero will zero the water level reading for the levelvent water level datalogger](/products/dataloggers-and-telemetry/3250-levelvent/instructions/user-guide/images/fig4-11-1x.jpg)
Figure 4-11 Datalogger Zero
After clicking Zero, the current time will be displayed as the "Last Zero Time".
Note:
You can not perform a Datalogger Zero while the datalogger is running.
![Datalogger Zero can be cleared using the Diagnostic Utility datalogger zero can be cleared using the diagnostic utility](/products/dataloggers-and-telemetry/3250-levelvent/instructions/user-guide/images/fig4-12-1x.jpg)
Figure 4-12 Last Zero Time
The Datalogger Zero can be cleared using the Diagnostic Utility. See Section 10.