Servomex NanoTrace DF-760E, Instruction Manual

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68 DF-760E User Interface
Zero Calibration, the Active Zero Offset value is reset to 0.00 ppb and then automatically
increments again as needed.
The Active Zero Offset is designed to operate when the zero baseline is falling at a rate
less than 0.1 ppb/hr as would be the case after 1-2 weeks of initial operation. If user
calibrations are performed sooner, the H
2
O readings may be decreasing too rapidly for the
Active Zero Offset feature to operate properly and negative H
2
O readings may result.
If the Active Zero Offset value reaches 5 ppb a warning message CAL ZERO will flash in
the system status block on the display instructing the user that a zero calibration should be
performed. The maximum amount of offset that can be applied by this feature is 5 ppb.
Any further downward trend (baseline cleanup) exceeding –0.3 ppb will result in negative
readings until the next user calibration is performed resetting the Active Zero Offset value
to zero.
If the Active Zero Offset feature is turned off, the User Zero Offset value will appear in its’
place in the CHECK/ADJUST ZERO menu. The previous user Zero Offset value (if any)
will reappear and immediately be applied to the live display readings. Likewise, if the
Active Zero Offset feature is on, then its’ value (if any) will appear and immediately be
applied to the live readings.
7.5.9.2 Signal Monitor
Figure 52: System Monitor
The Signal Monitor depicts 18 system parameters in numerical order. Each parameter is
unique for each system. In the event of a system error, these parameters can be used as a
diagnostic tool. See page 60 for additional information on system errors.
7.5.9.3 Purge Purifier
When installing or replacing a purifier, the plumbing is inevitably exposed to ambient air.
The key is to install the purifier quickly in order to minimize the duration of the exposure
and therefore reduce the amount of time it takes the analyzer to release moisture from the
wetted surfaces.