Ⅰ、Operational principle

The chlorophyll sensor uses leading optical technology, integrated design, high efficiency power management, rugged structure, stable sensor performance, maintenance-free and frequent calibration, and can be used online for a long time. It can be used for research, investigation and monitoring of rivers, lakes, ponds, marine surveys, aquaculture, drinking water sources, algae and phytoplankton conditions.

• 0～400ug/L

• Resolution: 0.1ug/L

• 0～50 °C; IP68 protection, water depth within 20 meters

• Built-in temperature sensor

• Support RS-485, Modbus/RTU protocol

• Convenient, fast, stable and easy to maintain

Ⅱ、Technical performance and specifications

1. Technical parameters

Ⅲ、Installation and electrical connection

1. Installation

Installation Distance Requirements: With the side wall to maintain more than 3cm, with the bottom to maintain more than 10cm.

2. Electrical connection

Cable for the 4-core twisted pair shielded wire, wire sequence definition:

• Red cord—power cord（12V～24VDC）

• Black cord —ground cord（GND）

• Blue cord—485A

• White cord—485B

• Yellow cord—Current output (if unused, suspended)

The wiring sequence should be carefully checked before power-on to avoid unnecessary losses caused by faulty wiring.

Wiring instructions: considering the cable long-term Immersion in water (including sea water) or exposure to air, all wiring are required to do waterproof treatment, the user cable should have a certain degree of corrosion resistance.

Ⅳ、Maintenance

1. Maintenance procedures and methods

1.1 Maintenance schedule

The cleanliness of the measurement window is very important to maintain accurate readings.

1.2 Maintenance methods

• Sensor outer surface: Clean the outer surface of the sensor with tap water. If there is still debris left, wipe it out with a soft, damp cloth. For some stubborn dirt, add some household washing liquid to the tap water to clean it.

• Check the cable of the sensor: the cable should not be tightened during normal operation, otherwise the cable inside the cable will be broken and the sensor will not work properly.

• Check the sensor's measurement window for dirt.

1.3 Notes

The sensors contains sensitive optical and electronic components. Make sure the probe is not subject to severe mechanical shock. There are no parts inside the probe that require user maintenance.

2. Sensor calibration

a) Zero calibration: Take an appropriate amount of distilled water in a brown beaker and place the sensor vertically in the solution. The front end of the sensor is at least 10 cm from the bottom of the beaker. After 3 to 5 minutes, the value is stabilized and zero calibration is performed. The instructions refer to the appendix.

b) Slope calibration: Place the sensor probe in the standard solution. The front end of the sensor is at least 10 cm away from the bottom of the beaker. After 3 to 5 minutes, the slope is calibrated after the value is stabilized. The instructions refer to the appendix.

Application Scenarios

The Yexsensor YEX-CHLO-406-S is designed for high-performance environmental monitoring across various sectors:

• Aquaculture Monitoring: Ensuring optimal algae levels for fish and shrimp health in ponds and intensive farming systems.

• Rivers and Lakes: Continuous tracking of water quality to detect early signs of algal blooms (eutrophication).

• Drinking Water Sources: Protecting intake reservoirs by providing real-time chlorophyll-a concentration data.

• Marine Surveys: Exploring oceanographic phytoplankton distribution at depths up to 20 meters.

• Wastewater Treatment: Monitoring the efficiency of biological treatment processes involving algae.

FAQ

Q1: How does the YEX-CHLO-406-S measure chlorophyll-a?
   A1: It utilizes fluorescence technology, emitting a specific light wavelength to excite chlorophyll molecules and measuring the resulting fluorescence to determine concentration without chemical reagents.

Q2: Does the sensor require frequent calibration?
   A2: No, the sensor is designed for long-term stability. While "maintenance-free" under standard conditions, calibration frequency should follow local regulatory requirements or specific project needs.

Q3: Can it be used in seawater?
   A3: Yes, the shell is made of 316 Stainless Steel, which provides excellent corrosion resistance for marine environments.

Q4: What happens if the power supply is reversed?
   A4: We strongly advise checking the wiring sequence (Red for Power, Black for GND) before power-on to avoid permanent damage caused by faulty wiring.

Q5: What is the maximum depth for installation?
   A5: The YEX-CHLO-406-S is IP68 rated and can operate safely at depths of up to 20 meters underwater.

Q6: How should I clean the optical measurement window?
   A6: Use tap water and a soft cloth. For stubborn dirt, use a mild household cleaning liquid. Avoid using abrasive tools that might scratch the lens.

Q7: Is the 4-20mA output included by default?
   A7: The standard interface is RS-485 (Modbus/RTU). The 4-20mA analog output is an optional configuration that must be specified at the time of order.

Q8: Can the cable length be extended beyond 5 meters?
   A8: Yes, while the standard length is 5 meters, Yexsensor offers custom cable lengths to suit your specific installation site requirements.