Onset Computer Corporation
HOBO U14
11
User’s Guide
Chapter Three:
Maintenance
Replacing the Internal RH Sensor
The internal relative humidity sensor in the U14-001 may require replacement if it is damaged mechanically or by exposure to
condensation or chemicals. The replacement sensor (Onset part number: HUM-RHPCB-3) is available from Onset or an Onset
Authorized Dealer.
You can replace the internal RH sensor yourself or have it replaced as part of a U14-001 tune-up/calibration service (available from
Onset).
Steps
NOTE
: To dissipate static electricity while you work, periodically touch an unpainted metal surface.
To replace the sensor:
1.
Remove the four screws on the back of the unit and open the case.
2.
Remove one battery to deactivate power to the sensor.
3.
Carefully remove the board and turn it over so the LCD is facing up.
The RH sensor is located on the upper left side of the board, adjacent to the LCD.
4.
Gently grasp the sensor and pull to the left, unplugging the sensor from the board.
5.
Firmly plug in the replacement sensor. The front of the sensor should face the front of the board (LCD screen side).
6.
Place the board back into the case (be careful not to dislodge the sensor).
7.
Reinstall the battery you removed.
8.
Replace the screws.
9.
Start the logger and check the accuracy of the RH readings.
Replacing Batteries
The HOBO U14 requires three AAA batteries. Onset Computer Corporation strongly recommends the use of fresh alkaline batteries.
Batteries should be replaced when the BATT LEVEL bar graph is down to one segment, which indicates 20% battery life or less.
To ensure data integrity, use HOBOware to read out the logger and stop logging before changing batteries.
