NovaLynx Corporation
255-704-B
Page 14
April 2021
6.3
Water Level Management
The logger can operate for long periods of time un-attended due to its very large memory capacity.
However, other factors must be considered to ensure the evaporation station is operating properly. A
regular maintenance period should be scheduled to inspect the evaporation pan, water replacement
system, and operation of the logger and evaporation gauge.
Evaporated water must be replaced. Ideally, the water level should be maintained from 7 to 8 inches
deep (175 to 200 mm) in the evaporation pan. In practice, keeping the level between 5 and 8 inches
deep (125 to 200 mm) is adequate. Do not overfill because the potentiometer may enter the dead band
where the readings would be "floating", resulting in meaningless data.
Water replacement can be accomplished by means of a NovaLynx 255-620-A Automatic Refill System,
if a water source is available. Otherwise the station will need to be visited often enough to keep the
water level within acceptable limits.
Upload the data regularly and process the data. Water that is added either manally or automatically
must be deducted from the evaporation totals. Water added by precipitation should also be deducted.
7
MAINTENANCE
At regular intervals, inspect the following:
Check under the evaporation pan for leaks.
Inspect the pipe between the pan and the analog evaporation gauge for leaks.
Make sure the automatic refill system shuts off completely between refills.
If the optional offset calibration (Section 5.5) was performed when the logger was installed,
compare the reading on the logger with the actual water level (
use a measuring stick
).
Note:
If the offset calibration was not done the measurements will not agree because the
generic calibration does not include an offset for the amount of water required to cause the
float to lift off the bottom of the pan.
Read the logger memory using a computer. Check the data to ensure the logger is recording
data properly.
From the HOBOware icon menu, select "Device status" and verify the battery is good and the
memory is not too full. Replace the two AAA batteries if needed (Section 8).
Be sure to "Start" the logger before disconnecting.
Disconnect the USB cable.
Install the logger in the enclosure.
Make sure the sensor cable on the bottom of the logger is plugged in all the way and the
display is showing the correct water level.
Verify the logger is LOGGING and the display updates every 15 seconds.
