Hanna Instruments HI 8001, Инструкция по эксплуатации

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can compensate for changes in the process variable (measurement) and is par-
ticularly good for slowly moving processes. When a change occurs in the pro-
cess the derivative action causes the controller gain to move the “wrong” way
until the measurement gets near the set point.
3.6 AGITATOR CONTROL
Each of the 4 fertilizer tanks may have an agitator.
An agitator can be activated in a specific tank prior to tank selection by an
irrigation program. The pre-agitation time can be set using panel
S 45 (SET
AGITATORS); the pre-agitation occurs only when the pre-irrigation time is set.
During the irrigation program, the agitators can be stopped (if working time is
zero), set to work continuously (if pause time is zero) and intermittently (if working
time and pause is different than zero).
The work and pause time can be set using panel
S 45 (SET AGITATORS).
The agitator settings are displayed on panel C 17 (AGITATOR STATE).
3.7 FILTER CONTROL
Fertigation Controller has the capability to check and automatically clean two
filters controlled by two filter-cleaning programs.
Each filter cleaning program can be started by the following conditions:
- Following one specified irrigation program. This irrigation program can
be set in panel S 46 (FILTERS CTRL) .
- When a “dirty filter” alarm is activated. Cleaning by this option is set using
panel S 46 (FILTERS CTRL).
- The working time for filter-cleaning programs can be set using panel S 46
(FILTERS CTRL).
3.8 MANUAL FUNCTIONS
The Fertigation Controller has the following Manual function capabilities:
- To switch the controller state between STOP, WORK and INIT, use panel S
49 (CONTROLLER STATE).
- The controller state can be checked using panel C 01 (GENERAL INFO).
- To manually start a program use panel S 47 (PROG MAN START).
- To manually stop a program use panel S 48 (PROG MAN STOP).
- To check and to change the value for each of the outputs, use panel S 50
(OUTLET MAN CTRL).