The A20CL is an industrial-grade online residual chlorine controller that may be configured in numerous ways and tracks precisely.Dual installation,wide range adaptability,and consistent performance are offered by TS-238-10M residual chlorine electrode and PP-86 electrode flow channel.
From 0-20.00ppm(mg/L),three temperature compensation methods,segregated signal output,and three intelligent relay alarms provide synchronous residual chlorine and temperature measurement.Because of its Chinese-English capabilities,sewage treatment,water supply,pharmaceuticals,chemicals,and food use it.The residual chlorine monitoring systems are effective and adjustable for different water quality.
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Features
Specifications
| Category | Specifications |
|---|---|
| Measuring Parameters | Residual Chlorine, Temperature |
| Measuring Range | Residual Chlorine: 0–20 ppm / 0.0–20.0 ppm / 0.00–20.00 ppm (switchable) |
| Measuring Accuracy | ≤±0.01 ppm |
| Resolution | 0.01 ppm |
| Stability | ≤0.02 ppm/24 hours |
| Temperature Compensation | 0–100℃, Manual / Automatic (PT1000 / NTC10K), 3 options available |
| Signal Output | 1 group of 4-20mA isolated output (for Residual Chlorine or Temperature); Optional: 2 groups of 4-20mA output or RS485 (ModBus RTU) communication; Maximum load: 500Ω |
| Alarm Output | 3 groups of normally open contact relays (3A/250VAC), support high/low point switching with adjustable hysteresis |
| Operation & Display | Bilingual interface (Chinese/English), LCD backlight screen (30s/60s/120s/Always On adjustable), menu-guided operation |
| Safety & Protection | Password protection function, IP65 protection class, anti-electromagnetic interference |
| Physical Dimensions | Overall Dimensions: 144×144×115mm (H×W×D); Cutout Size: 138×138mm (H×W) |
| Power Supply & Consumption | Power Supply: AC220V or DC24V; Power Consumption: ≤7W |
| Operating Environment | Temperature: 0–50℃; Humidity: ≤85%RH (no condensation) |
| Standard Configuration | A20CL Main Unit, TS-238-10M Residual Chlorine Electrode, PP-86 Electrode Flow Cell, Fixing Accessories, Special Signal Cable, Operation Manual |
Standard Configuration
- Host:A20CL
- Residual chlorine electrode: TS-238-10M
- Electrode flow channel: PP-86

Core Highlights
- It is accurate to within 0.01 ppm throughout the range and operates with concentrations between 0 and 20 ppm.It can be applied in both high and low levels of residual chlorine and remains stable for a whole day.
- Multi temperature reinforcement adaptation: Supports PT1000, NTC10K automatic and manual temperature compensation, covering a temperature range of 0-100 ℃, with strong environmental adaptability.
- Intelligent alarm control: Three sets of relays support 8 modes including high point, low point, and within/outside the interval, with adjustable hysteresis to avoid frequent on-off, and can be linked to cleaning devices and other equipment.
- Rich extension functions: The basic model includes a set of signal outputs, and two sets of outputs or RS485 communication can be selected as needed, making it easy to connect with the central control system.
Featured Applications
- Municipal water: We test the residual chlorine in the pipelines and the effluent from the water plant to make sure they are safe to drink and carry.
- Food and drug firms must preserve residual chlorine in the water used during production to make sure the products are of good quality and meet health and safety standards.
- To keep things flowing and avoid corrosion, the chemical and energy industries need to keep an eye on the temperature and chlorine levels in the cooling water.
- Examples of big water purification projects that make things safer and more flexible are commercial systems and pool water quality monitoring.
- After cleaning, keep an eye on the low chlorine level to make sure the environment is safe and stop secondary contamination.

Daily maintenance and precautions
Installation and usage precautions
- Installation should avoid high temperature, high humidity, corrosive environments, and direct sunlight to ensure IP65 protection. The working environment temperature should be controlled between 0-50 ℃.
- The transmission of electrode signals must use dedicated cables and cannot be replaced by ordinary wires. When wiring, distinguish WE, CE, and RE terminals to avoid misconnection.
- It is recommended to supply power separately and not share it with equipment such as dosing machines and mixers to reduce power surge interference and ensure signal stability.
- Zero point calibration requires chlorine-free distilled water, while slope calibration requires stable water samples for 15 minutes and laboratory data adjustment without chemicals.
- To prevent overload damage and preserve the instrument interface, an auxiliary relay with suitable current resistance should be configured when the relay is linked to external equipment.
Key daily maintenance points
- Instrument maintenance: Regularly clean the instrument casing to avoid contact with organic solvents such as toluene and xylene; Before long-term use, it is necessary to restore the factory settings and cut off the power, and store it properly.
- Electrode maintenance: The electrode needs to be regularly cleaned of the membrane to avoid contamination affecting the measurement; The electrolyte should be replaced regularly (according to the usage frequency of 2 weeks to 2 months), and the membrane should be replaced promptly if it is damaged.
- Calibration cycle: It is recommended to perform zero point and slope calibration once a month. For scenarios with large temperature fluctuations or complex water quality, it can be shortened to once every two weeks.
- Whether the signal output isn’t normal, check to see whether the cable is broken or the wiring is loose. Before recording data drift, make sure to calibrate or check the status of the electrode.
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You can use the A20CL online residual chlorine controller to find out how much chlorine is left in industrial water. It grows quickly and may be set up in two distinct ways to handle different situations. It is great for city water supply, factory production, daily monitoring, and compliance management because it always works, is easy to set up, and doesn’t need much maintenance.
The A20CL water quality safety companion is accurate, flexible, and easy to carry. We employ accurate tools and offer a wide range of services to make the water better.
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