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The MV7 series Specific Ion Sensors are based on ISE (ion selective electrode) to measure the concentration of the ion in solution, the electrode detects the activity of free ion, not a complex version.
Some ions only exist in a specific pH range as free ions and compound outside this PH range, so the measurements may need PH adjusting buffer and PH compensation can be made by using the GDC, multiple channel Display and Controller with a pH sensor to determine the total ion concentration.
Most specific ion sensors are subject to interfering ion which is similar by sizing and electric changing in the solution, knowing all the contents in the solution is important before a real measurement is made.
Principle of Electrochemical
Ion-Selective Electrodes (ISEs) are sensing elements that are designed to respond selectively to ions in an aqueous solution.
When the reference half-cell and the sensing half-cell are combined into the same body housing, they are referred to as a “combination” electrode.
Delta-Phase incorporates Combination ISE cartridges into standard MV7 Field Rebuildable sensors that widely cover pION measurements including most municipal water and wastewater, surface water and industrial process water and wastewater.
These specific ion electrodes are popular for many applications due to their convenience, affordability and accuracy.
The MV7 sensors are ideal for both portable handheld and stationery in-situ applications, offering quick time response, minimal flow dependence and low power consumption.
The cartridge electrode features a “long life” reference element eliminating the need to frequently replace the electrode cartridge.
By using fixed electrodes, optional disposable sensors are suited for many special applications.
Both rebuildable and disposal sensors come with different mounting types such as immersion, flow-cell and insertion /retractive ball-valve assembly installations.ISEs Typically Utilize One of 4 Primary Sensor Types:
Polymer Membrane – This common sensor design incorporates ionophores or other ion-exchange agents that are specific to the ion of interest, into an inert matrix such as PVC. A millivolt potential develops at the surface of the membrane and accurately correlates to the ion concentration. Sensors of this type include: NH +, Ca 2+, BF - , NO -, K +, and Surfactant.
Solid State – These sensors utilize relatively insoluble inorganic salts within a hard pellet or crystalline matrix that allows the detection of specific ion activity. These sensors are both accurate and one of the longest lasting ISE sensor types. Periodic buffing helps to restore performance under especially harsh conditions. Sensors of this type include: Br- , Cd2+ , Cl- , CN- , F- , I- , Pb2+ , S2- , Ag2+ , and SCN-.
Gas Sensing – With a gas permeable membrane, an internal buffer solution, and the use of ionic strength adjustors, these sensors enable accurate detection of ions such as NH3 , CO2 , NOX and others.
Glass Membrane – Similar to pH sensors, these ISEs use a special glass formula to be selective for a specific ion. Na+ is currently the only common parameter for this type of ISE.
Specifications
Measuring Range
Depends on parameter and application, (consult factory)
Accuracy/Resolution
Depends on parameter and application, (consult factory)
Temp. Compensation
Pt1000, 0 to 100°C Automatic.
Respond Time
T90 approx. 10s
Operate Pressure
0 to 100 psig (6.9Bar) standard. Optional HP sensor up to 300 psig (21Bar) (consult factory)
Operate Temp.
32 to 149°F (0 to 80°C), Depends on parameter and application (consult factory)
Power Supply
12 to 30VDC, the maximum consumption 0.5W
Interface
RS485 Modbus RTU standard, mv signal for analog sensors.
Material
Glass/Ceramic, PVC standard. Optional 316L, PP (consult factory for others)
IP Rating
>IP68, submersible
Weight
1.9 pound (0.85kg), standard (consult factory for optional sensor configurations).
Dimension
Dia. 1.54” × 11” (OD. 39.2 × 276 mm) standard. More size available, consult factory.
Mounting
Immersion/Insertion, Optional Insertion with Retractive ball-valve Assembly and “T” handle.
Measuring Parameters and Performance
Parameters
Range @ 25°C
Sensing Element
Operate Temp.
Repeatability
pH Demand
Known Interferences
Ammonia
NH3
0.01 to 17,000
ppm
Gas Sensing
0 to 50°C
±2%
>11
Volatile Amines
Ammonium
NH + 4
0.02 to 18,000
ppm
PVC
Membrane
0 to 50°C
±2%
4 to 10
K+, Na+
Bromine
Br-
0.2 to 79,900
ppm
Solid State
0 to 80°C
±2%
1 to 12
I-, Cl-, S2-, CN- and NH
3
Divalent Cadmium
Cd2+
0.0 to 11,200
ppm
Solid State
0 to 80°C
±4%
2 to 10
Hg2+, Ag+ & Cu2+ must be absent, high levels of Pb2+ & Fe2+
Calcium
Ca2+
0.02 to 40,100
ppm
PVC
Membrane
0 to 40°C
±4%
2 to 11
Pb2+, Hg2+, Cu2+, Ni2+, Fe2+
Chloride
Cl-
1.8 to 35,000
ppm
Solid State
0 to 80°C
±2%
2 to 12
CN-, Br-, I-, & S2- must be absent
and NH3
Carbon Dioxide
CO2
4.4 to 440 ppm
Gas Sensing
0 to 50°C
±2%
4.8 to 5.2
Volatile Weak Acids
Copper
Cu2+
0.064 to 6,450
ppm
Solid State
0 to 80°C
±4%
2 to 6
Hg2+ & Ag+ must be absent; high
levels Fe2+, Br- and Cl-
Cyanide
CN-
0.2 to 260
ppm
Solid State
0 to 80°C
±2%
10 to 14
I-, Br-, Cl-, S2- must be absent
Fluoride
F-
0.02 to Saturated
Solid State
0 to 80°C
±4%
5 to 7
OH-
Iodide
I-
0.0064 to
127,000 ppm
Solid State
0 to 80°C
±2%
0 to 14
CN-, S O 2-, Cl-, S2-, NH
2 3 3
Lead
Pb2+
0.2 to 20,700
ppm
Solid State
0 to 80°C
±4%
4 to 7
Hg2+, Ag+, Cu2+ must be absent; Fe2+ & Cd2+
Nitrate
NO -
3
0.4 to 62,000
ppm
PVC
Membrane
0 to 40°C
±2%
2.5 to 11
CIO -, I-, ClO -, F-
4 3
Nitrite
NO -
2
1.6 to 6,400
ppm
PVC
Membrane
0 to 40°C
±4%
2 to 12
Potassium
K+
0.04 to 39,000ppm
PVC
Membrane
0 to 40°C
±2%
2 to 12
Cs+, NH +, TI+, H+, Ag+, Tris+, Li+,
4
Na+
Silver
Ag+
0.01 to 107,900ppm
Solid State
0 to 80°C
±2%
2 to 12
Hg2+
Sodium
Na+
0.1 to 23,000ppm
Glass Membrane
0 to 80°C
±2%
>9
H+, K+
Sulfur
S2-
0.003 to
32,100ppm
Solid State
0 to 80°C
±4%
>11
Hg2+
Surfactant
X+/Y-
End point indicator
PVC
Membrane
0 to 40°C
Thiocyanate
SCN-
0.29 to 58,100
ppm
Solid State
0 to 50°C
±4%
2 to 10
I-, Br-, CN-, NH , S O 2-, Cl-, OH-,
3 2 3
S2-
-
APPLICATIONS
Water and Waste water treatment
Ammonium, Nitrate, Calcium, Chloride-ion, Fluoride-ion, and so on.
Surface Water
Ammonium, Bromide, Nitrate, Calcium, Chlorideion, Fluoride-ion, Sodium, Potassium, Silver, Copper, etc.
Typical Industrial Applications
■ Mining: Calcium, Cyanide, Fluoride-ion.
■ Metallurgy: Copper, Cyanide, Fluoride-ion,Nitrate.
■ Pharmacy: Calcium, Fluoride-ion,Ammonium, Iodide.
■ Semiconductor: Fluoride-ionFEATURES & BENEFITS
Measuring Specific Ion & Temperature
Robust pION & Temperature sensors.
Digital sensor with reliable RS485 communication.
Plug and play with GDC series terminals or computers with Delta-Phase ViewTM software.
Calibration history data stored in sensor, Easy to recalibrate.
Lightning and surge protection for worry-free power.
Optional Self-Diagnosis function.
Optional Analog sensor for two-wire application.
Rebuildable sensor using cartridge electrode.
Optional disposal sensor for special applications.
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MV7 ion selective electrode sensor
- Digital and Rebuildable A Analog and Rebuildable Sensor
D Digital and Disposal Sensor AD Analog and Disposal Sensor
Measuring Parameter
-NH4 Ammonium
-Ca Calcium
-Cl Chloride
-CN Cyanide
-F Fluoride
-NO3 Nitrate
-K Potassium The other parameters see the “Measuring Parameters and Performance” table above
Mounting
- 3/4” NPT Back Thread for Immersion mounting of rebuildable sensors
-N0 1.5” NPT Compress Fitting for rebuildable sensors flow-cell mounting
-N1 1” NPT compress Fitting for rebuildable sensors inserting installation
-N2 3/4” NPT Compress Fitting for disposal sensors (Immersion/Insertion Mounting)
-R0 Rebuildable sensors inserting with 1-1/4” NPT Retractive Ball-valve Assembly
-R1 Disposal sensor inserting with 1” NPT Retractive Ball-valve Assembly
Material of Housing
- Standard PVC
-SS 316L Stainless Steel
-PP Polypropylene Other housing material contact factory
Length of Housing
- Standard 12”
X17 17” (Min. length for Retractive Ball-valve Assembly Mounting)
X21 21” Other length of housing please contact factory
Length of Cable
-C10 10 ft, approx. 3 m
-C20 20 ft, approx. 6 m
-C30 30 ft, approx. 9 m Other length of cable please contact factory
MV7
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-Cl
-R1
-PP
X17 -C30