Servomex NanoTrace DF-760E, Инструкция по эксплуатации

Страница: 71 / 182

User Interface DF-760E 67
7.5.9 Moisture Diagnostics Menu
Figure 50: Diagnostics SubMenu
7.5.9.1 Active Zero On/Off
Figure 51: Moisture Active Zero Setup Screen
The Active Zero Offset feature is designed to automatically compensate for the analyzer’s
gradual zero baseline cleanup. This gradual cleanup is natural and occurs after a fresh
startup or after a prolonged or abnormally high moisture exposure. This feature ensures
that accurate low ppb H
2
O readings can be made as soon as possible after initial startup, or
after a high H
2
O upset event. It is similar to the User Zero Offset feature in that a small
positive offset is added to the analyzer H
2
O readings (display and output) to compensate
for the long term downward trending in the readings during cleanup. The Active Zero
Offset provides an automatic addition of offset that occurs in miniscule steps, and within
set guidelines, corresponding to predictable behavior during cleanup.
When Active Zero Offset is enabled through the Diagnostics Menu, the User Zero Offset
feature is disabled and vice versa. While the User Zero Offset feature requires the user to
enter a fixed positive offset value to accommodate the baseline cleanup, the Active Zero
Offset does so automatically, and only when necessary.
The current Active Zero Offset value is shown in the Check/Adjust Zero screen as shown
in Figure 22. It starts at a value of 0.00 ppb when the analyzer is first turned on, and then
increments automatically as the analyzer applies offset to the readings. After each User