For maximum safety in the production of clean water, it is essential to chlorinate to the point of establishing a level of residual chlorine. Knowing that the treatment has been properly carried out can only be established by using testing equipment capable of measuring this level of residual chlorine.
Residual Analyzers including Reagentless Chlorine Analyzers, Fruit Washing Chlorine Analyzers, and High Range Chlorine Analyzers
Applications
- Municipal Drinking Water
- Municipal Waste Water Effluent
- Cooling Tower
- Fruit Washing Chlorine Analyzer
- Vegetable Washing Chlorine Analyzer
- Rubber Processing
- Pool & Spa
Definition of Terms & Types of Chlorine Commonly Measured
Residual Chlorine – The available chlorine remaining after the reaction interval and still available to combat the more resistant organisms and to safeguard against any later contamination.
Free Chlorine – The portion of the total residual chlorine remaining in the chlorinated water or waste at the end of a specified contact period, which will react chemically and biologically as hypochlorous or hypochlorite ion.
Applications typically measuring free chlorine residual include:
- Municipal Drinking Water
- Cooling Tower
- Fruit & Vegetable Wash-down
Combined Chlorine – The portion of the total residual chlorine remaining in the chlorinated water or waste at the end of a specified contact period, which will react chemically and biologically as chloramines or organic chlorine.
Total Chlorine – The sum of both the Free Chlorine residual and Combined Chlorine residual.
Applications typically measuring total chlorine residual include:
- Municipal Waste Water Effluent
- Pool & Spa
Measurement Methods
Colormetric – Uses DPD reagents that cause a chemical reaction to change the color of the water. A photocell is use to determine the residual concentration of the sample based on the color change.
Amperometric: Open Cell – Uses two electrodes in direct contact with the sample water with the sample water acting as an electrolyte. An electrical signal is produced proportional to the residual concentration. The monitor is able to determine the residual level of the sample water based on the strength of this electrical signal.
Amperometric: Probe – Uses two electrodes submerged in an electrolyte behind a permeable membrane. The target disinfectant species is able to permeate through the membrane where it can read. An electrical signal is produced proportional to its concentration. The monitor is able to determine the residual level of the sample water based on the strength of this electrical signal.
Potentiostatic: Probe – Uses a three electrodes that operates in the same fashion as the Amperometric: Probe style.
Hydro Instruments Residual Analyzers
Model No. RAH-210
Applications
Municipal drinking water, Municipal waste water effluent, Cooling tower, Fruit & Vegetable wash-down, Pool & Spa
Disinfectant
Free Cl2 or Total Cl2
Measurement Method
Amperometric: Open Cell
Key Benefits
- Versatile and field adjustable measurement range
- Tolerant to less than optimal water quality
Advantages
- Readings are not affected by air bubbles
- Inexpensive maintenance
- Self-cleaning measurement electrodes
Disadvantages
- Sample water pH must be compensated for
- Total Cl2 measurement requires KI reagent
- Moving parts
- Water cannot contain corrosion inhibitors
Model No. RAH-280
Applications
Municipal drinking water, Municipal waste water effluent, Cooling tower, Fruit & Vegetable wash-down, Pool & Spa
Disinfectant
Free Cl2 or Total Cl2
Measurement Method
Amperometric: Open Cell
Key Benefits
- Versatile and field adjustable measurement range
- Tolerant to less than optimal water quality
- Large 320×240 pixel, color graphical display
- Live graph charting
Advantages
- Readings are not affected by air bubbles
- Inexpensive maintenance
- Self-cleaning measurement electrodes
Disadvantages
- Sample water pH must be compensated for
- Total Cl2 measurement requires KI reagent
- Moving parts
- Water cannot contain corrosion inhibitors
Model No. RPH-250 (Reagentless Analyzer)
Applications
Municipal drinking water, Cooling tower, Fruit & Vegetable wash-down, Rubber processing, Pool & Spa
Disinfectant
Free Cl2, Total Cl2, Chlorine Dioxide… (Others available, see RPH-250 product literature)
Measurement Method
Amperometric: Probe or Potentiostatic: Probe
Key Benefits
- Wide range of disinfectant sensors available to meet application needs
- High range chlorine analyzer. Can be used for applications requiring a very high range of residual measurement
- Reagentless chlorine analyzer
Advantages
- Inexpensive maintenance
- Very easy and simple maintenance
- Self-cleaning measurement electrodes* (Air bubbles in the sample do not affect reading.)
Disadvantages
- Free Cl2 measurement requires sample water pH compensation
- Air bubbles in the sample can affect readings
- Changes in sample water pressure and flow can affect readings
- Requires periodic control of sensor signal
(*) Only for F3 and D3 disinfectant sensors
Model No. RPH-260 (Reagentless Analyzer)
Applications
Municipal drinking water, Cooling tower, Fruit & Vegetable wash-down, Rubber processing, Pool & Sp
Disinfectant
Free Cl2, Total Cl2, Chlorine Dioxide… (Others available, see RPH-260 product literature)
Measurement Method
Amperometric: Probe or Potentiostatic: Probe
Key Benefits
- Wide range of disinfectant sensors available to meet application needs
- High range chlorine analyzer. Can be used for applications requiring a very high range of residual measurement
- Reagentless chlorine analyzer
- Up to two (2) different disinfectant sensors can be used simultaneously
- Large 320×240 pixel, color graphical display
- Live graph charting
Advantages
- Inexpensive maintenance
- Very easy maintenance
- Self-cleaning measurement electrodes* (Air bubbles in the sample do not affect reading.)
Disadvantages
- Free Cl2 measurement requires sample water pH compensation
- Air bubbles in the sample can affect readings
- Changes in sample water pressure and flow can affect readings
- Requires periodic control of sensor signal
(*) Only for F3 and D3 disinfectant sensors
