Hanna Instruments hi 9914 User Manual
19
- When the water is good for irrigation, the Feed OK LED is ON.
- If any alarm condition occurs (see pag.22), the ALARM LED turns ON.
- If any alarm condition occurs (see pag.22), the ALARM LED turns ON.
The controller can be restarted by pressing the
RESET button.
RESET button.
If the alarm condition is still present, the controller goes back in alarm
status.
When the controller is powered, the actual pH and conductivity values
are displayed on the two LCDs in pH and mS/cm units respectively.
status.
When the controller is powered, the actual pH and conductivity values
are displayed on the two LCDs in pH and mS/cm units respectively.
NORMAL OPERATION
When the HI 9914 controller is turned on, the meter performs a status
check of the level sensors and provides the commands depending on the
input status.
All the inputs have a delay of about 1 second in order to avoid wrong
commutations caused by the waves.
check of the level sensors and provides the commands depending on the
input status.
All the inputs have a delay of about 1 second in order to avoid wrong
commutations caused by the waves.
Step 1:
At start-up the controller checks the normal level and low-level sensors.
• If the tank is empty, both sensors are open and the controller goes
At start-up the controller checks the normal level and low-level sensors.
• If the tank is empty, both sensors are open and the controller goes
to step 2.
• If the low-level sensor is closed and the normal level sensor is open (the
water level is between low and normal level), the controller goes to
step 3.
step 3.
Step 2:
The water nozzle is activated (open) and the tank is filled with water.
When the low level is reached, the controller goes to step 3.
• If the controller remains in this status for more than 30 seconds, an
The water nozzle is activated (open) and the tank is filled with water.
When the low level is reached, the controller goes to step 3.
• If the controller remains in this status for more than 30 seconds, an
alarm condition occurs.
Step 3:
The water nozzle is open, the circulation pump is running and the tank
is filled with water.
When the normal level is reached (the normal level sensor is closed) the
controller goes to step 4.
The water nozzle is open, the circulation pump is running and the tank
is filled with water.
When the normal level is reached (the normal level sensor is closed) the
controller goes to step 4.