Hanna Instruments HI 8000 Series - Manual (Page 62)

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- Total number of sectors = 1
- Irrigation time = 15 minute
2. Go to panel S 38 (SET SECTORS) and check the above settings. If they are
different adjust them.
3. Set the reference value for EC and the range for its allowable variation (any
sensor’s input value that exceeds this range will trigger an controller the alarm)
in panel S 41 (COND CONTROL).
4. Make sure that all the other programs are stopped. For each program (from
1 to 9) we are going to set in panel S 32 (WORKDAY) for the current day an
“N” (inactive).
5. Check in panel S 08 (WORKDAY) if the working period for program 10 is
valid for the day in which we made the tuning (the current day). If not proceed
to set it in panel S 32 (WORKDAY).
6. Set in panel S 59 (SET LOG LEVELS) the following options: Recording level =
01; Consulting level = 01. This means that consulting the log is going to be
made for the sensors’ value and the registrations in log are going to be those
read by the sensors (for pH, respective EC).
With the above settings we are going to have an irrigation time set in panel S 38
for a single sector. The starting conditions are going to be those for manual
starting - from panel S 47 (PROG MAN START).
Next we are going to set the PID parameters for EC in panel S 57 (SET PID
PARAMS), as follows:
ECk = 1.0
ECTi = 99.9
ECTd = 0.0
With the above settings we are going to have a Proportional setting for EC.
7. Start manually program 10 from panel S 47 (PROG MAN START) and wait
until the setting time expires (15 minutes default).
8. After the program ends consult the log table. From this you are going to write
down in a table the sensor’s EC readings and the time when the reading has
been done (see Section 4.10, LOGGING (DIARY) FUNCTIONS).
9. With the obtained data, make a drawing having as horizontal axis the time
and vertical axis the EC variations. Analyze the obtained chart.
10. Increment the gained amplification constant’s value (ECk) in panel S 57
(SET PID PARAMS). Repeat the steps 7, 8, 9 and 10 until the wave corre-
sponding to the EC variation is sinusoid type that has approximately constant
amplitude (unamortized oscillation).