SECTION 13___
MEASUREMENT AND CONTROL INSTRUMENTATION
PART 1
1.01
DESCRIPTION
A.
1.02
1.03
Section includes analyzer for monitoring and/or controlling free residual
chlorine, chlorine dioxide or ozone with pH or redox/ORP.
MEAUREMENT AND CONTROL PROCESS
B.
The general method of measuring free chlorine, chlorine dioxide, redox,
and/or pH will be a flow-through amperometric type measurement system
with optional temperature and pH compensation.
C.
The method will be augmented by a potentiostatic design for increased
accuracy.
D.
The method will be United States EPA accepted under Method 334.0.
E.
The method of control shall be continuous close-loop, feed-forward, and
feed-back trim process. Device shall be capable of sending analog or
contact control signal to chemical feed pumps, chemical generator,
recording device or similar devices.
ALTERNATIVES
D.
1.04
GENERAL
Other methods of chlorine measurement, such as colorimetric chemistry
or amperometric without potentiostatic design are not acceptable.
SYSTEM DESCRIPTION
E.
Performance Requirements
a. Measurement range:
1. 0 to 50 mg/l of free chlorine or chlorine dioxide residual
2. 0 to 5 mg/l of ozone
3. pH of 0 to 14
4. ORP/Redox of -1500 to +1500 mV
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Project Name
11___-1
Project No.
b.
c.
d.
e.
1.05
CERTIFICATIONS
A.
B.
C.
1.06
Operational Criteria
a. Sample flow rate: 5.3-11.9 GPH (20 – 45 l/hr)
b. Sample pressure: 3 to 43.5 psi (0.2-3 bar) with minimum 3 psi
differential pressure
c. Sample water temperature: 32-104°F (0-40°C)
d. Ambient temperature: 32-113°F (0-45°C)
e. Operating humidity: 90% at 104 degrees F (40 degrees C) maximum
WARRANTY
A.
1.08
CE approved
EN 61000-3-2 and -3-3
EN 61010-1
ENVIRONMENTAL REQUIREMENTS
A.
1.07
Accuracy: +/- 5% of range limit value
Minimum detection limit: 0.02 mg/l (chlorine/chlorine dioxide/ozone)
Resolution: 0.01 mg/l (chlorine/chlorine dioxide/ozone)
Cycle time for each measurement: continuous and immediate
The equipment/system warranty, unless otherwise stated, shall be
warranted to be free of defects in material and workmanship for a period
of 24 months from the date of installation, but not more than 30 months
from the date of manufacture.
MAINTENANCE SERVICE
A.
Scheduled maintenance:
a. Electrodes and sensors: annually
PART 2 PRODUCT
2.01 MANUFACTURER
A.
Grundfos
1.
Model DIA-2Q
2.02 MANUFACTURED UNIT
______________________________________________________________________________
Project Name
11___-2
Project No.
A. The DIA-2Q chlorine analyzer consists of a preassembled assembly
containing a measuring cell, analyzer, and electrodes. All components are
completely assembled and wired for user friendly installation.
B. The DIA-2Q analyzer is housed in an IP65 rated enclosure.
2.03 EQUIPMENT
A.
Operational power shall be (115/120 VAC,50-60Hz)(24VDC)(230/240VAC,
50/60Hz) single phase power.
B.
The following operation modes shall be available:
i.
ii.
iii.
iv.
On/Off control through digital contact
Digital pulse frequency control
Digital pulse duration control
Analog P,PI, or PID control where the 0/4 to 20 mA signal from
the analyzer is scaled to pace the pump or generator
v. Compound loop to compensate for flow fluctuations.
C.
Output
i.
ii.
iii.
iv.
D.
Alarms
i.
ii.
iii.
iv.
2.04
Alarm NO/NC Contact
Pulse frequency relay
Pulse duration relay
Four Analog 0/4 to 20 mA outputs:
1. Residual
2. pH
3. Temperature
4. PID Controlled output
Low/High residual or pH alarms
No sample flow
Cleaning motor Alarm
Control alarms
COMPONENTS
A.
Standard equipment:
______________________________________________________________________________
Project Name
11___-3
Project No.
a.
b.
c.
d.
e.
f.
2.05
Analyzer
Measuring cell with temperature and sample flow monitoring
Chlorine/Chlorine Dioxide/Ozone residual and pH or ORP electrodes
All items installed and wired on wall mounting kit
Three reagent kit for pH calibration
Installation and Operation manual
B.
Dimensions
a. Width: 19.5 inches (495 mm)
b. Height: 19.5 inches (495 mm)
c. Depth: 4.8 inches (125 mm)
C.
Weight: 12 pounds (5.5 kg)
D.
The measuring cell shall be pressure-proof with motorized element for
electrode cleaning. Additional cell components shall include integral filter,
flow regulator, sampling valve, flow sensor and temperature sensor. The
cell manufacturer shall supply a back pressure valve mountable on the cell
discharge to ensure proper sample flow differential pressure.
OPERATION
A.
B.
C.
D.
The Analyzer shall be able to provide an analog control signal after
applying a P, PI or PID controller to the measured values.
The analyzer should be able to provide a compound loop control signal
that accounts for flow fluctuations.
The analyzer should be able to compensate for pH, temperature and flow
fluctuations.
The analyzer shall be equipped with a calibration function that calculates
the slope of the measured values in mg/l against a micro-amp signal from
the cell.
2.06 CONTROL
The analyzer shall come equipped with at least 3 menu selectable control modes; interpulse, pulse frequency, continuous control.
A.
Interpulse
1. The analyzer will provide a relay output for which the pulse width is
controlled for ON/OFF operation.
______________________________________________________________________________
Project Name
11___-4
Project No.
B.
Pulse frequency
1. The analyzer will provide a switching relay output of varying frequency
to perform proportional control based on pulses.
C. Continuous Control
1. The analyzer will provide a 0/4-20mA output for proportional, set-point
or compound loop control with P,PI or PID internal setting option.
D. The analyzer will also provide an option to select between setpoint or
combined control where the approach to the setpoint can be upward or
downward.
E. An optional mode should also include a three point controlled output: Closed,
half scale and full scale for applications where motorized type valves or
servomotors are required.
PART 3: EXECUTION
3.01
INSTALLATION
A.
3.02
WARRANTY
B.
4.01
The equipment shall be installed per the contract documents and
manufacturer’s recommendations.
The equipment/system warranty, unless otherwise stated, shall be
warranted to be free of defects in material and workmanship for a period
of 24 months from the date of installation, but not more than 30 months
from the date of manufacture.
ACCESSORIES
A.
Optional recommended accessories shall include:
1.
2.
3.
4.
5.
Pressure regulation valves for inlet and outlet
100 micron filter (if necessary)
Isolation valves for service on the cell
External strainer assembly.
Spare electrodes
______________________________________________________________________________
Project Name
11___-5
Project No.