Recorder Output - Hanna Instruments PCA 311 Instruction Manual

Note:
Acid/alkali Dosing Relay
Note:

Recorder Output

Proportional dosing pump
The bromine dosing is stopped when the concentration is over
Alarm high setpoint or when a System error related to bromine
measurement occurs.
Acid/alk dosing relay is activated (Common con-
nected to Normal Open) depending on the setpoint
and selected delta. If the analyzer is set to dose
acid, the relay is active when the pH value is over
the setpoint. If alkaline is dosed, the relay is acti-
vated when the pH value is under the setpoint.
The DOSING ACID/ALK. LED is turned on when the dosing
relay is closed.
The acid/alk dosing is stopped when system error related to
pH occurs.
The recommended recorder hookup uses a
twisted pair shielded cable. The shield should
be connected to the terminal at the instrument
end and left open at the recorder end.
To operate with this hookup, the following
conditions are required at the recorder end:
• The input to the recorder must be isolated from the chassis
ground (earth) of the recorder;
• If the recorder has more than one input, they must be
differential inputs.
Several type of outputs are available: 0-10mV, 0-100mV, 0-1V,
0-20 mA or 4-20 mA. The recorder output could be assigned
to Br, pH, Temperature or ORP .
A proportional dosing pump could be connected to the 4-20 mA
output. The pump could be used to dose bromine or acid/alk as
selected by the user. When the output is 4 mA, the pump must
be stopped and when the output is 20 mA, the pump must
provide the maximum output.
DOSING DOSING
pH pH
C NO
RECORDER
V
I
I
2 5