In-Situ Con TROLL PRO Operators Manual (purchased before 10 May 2012) - Manual (Page 19)

Calibrating the Probes 19
3.3.2 Zeroing the Pressure Sensor (Air Only)
Like the Level TROLL instruments, Aqua TROLL has been factory-calibrated with
NIST standards to a greater degree of accuracy than can be achieved in nearly any
alternate setting.
The pressure sensor in an Aqua TROLL can be “zeroed” in air, but should never be
“zeroed” in water. Overall, In-Situ Inc. does not recommend zeroing the pressure
sensor.
3.3.3 Restoring Defaults
Restore the Defaults if you have zeroed the Aqua TROLL level measurement or
calibrated the conductivity sensor and wish to return to the factory settings.
1. From the Con TROLL PRO Main menu, select Calibrate, Aqua TROLL, then
Defaults.
3.4 CALIBRATION HINTS
3.4.1 Nominal Stability vs. Full Stability
To meet the criteria for a valid calibration point, the change (Delta) in sensor
response is monitored over time. The controller is looking for the calibration
solution temperature and the sensor readings to settle over a specific time period.
The criteria for Full Stability are designed to meet the published specifications. The
criteria for Nominal Stability are designed to shorten the calibration time when an
approximate calibration is acceptable.
3.4.2 Factory Recalibration
Proper maintenance can improve your results and extend the life your probe. When
your probe is overdue for a factory recalibration or the RDO PRO requires a new
cap, the wrench symbol (
) will appear on the display.
• Factory recalibration of the Aqua TROLL instruments should be performed
every 12-18 months.
• Factory recalibration of the Level TROLL instruments should be performed
annually.
• RDO PRO sensor caps must be replaced annually.