About 71% of our planet is water, and not all that water is fit for different uses. It is because water quality differs, and its quality is a vital component for making water useful for different things. Uses of water include daily domestic consumption and industrial processes. To make water fit for such uses, water quality sensors are a wonder of technology that gives complete details about the safety and purity of water.
The basics of water and types of water quality sensors
When we talk about water quality, it is not only about the clarity of water. Instead, it covers different parameters, including:
· Turbidity
· PH levels
· Microbial content
Different water applications require different quality parameters, and with these sensors, we can easily get detail information about water quality. Since one sensor cannot cover all the testing, there are different sensors we use for water, including the following:
1. Physical sensors help in measuring things like turbidity and temperature.
2. Chemical sensors can measure nutrient concentration, pH level, and dissolved oxygen information.
3. Biological sensors detect the presence and percentage of biological organisms in water.
Each of these sensors uses a different technology. For example, chemical sensors use electrochemical methods, physical sensors use optical technology, and biological sensors use microbial detection technology.
Step-by-step working of water quality sensors
The working of these sensors is divided into multiple steps that are a part of the whole process. So, here are the details about all the events happening in each step:
1. Installation
The first step in this process is deployment, placement, and installation. It is important because the sensor needs to be in the perfect spot to measure the water's quality. It is important that the detection element, also known as the sensor probe, comes in direct contact with the water sample.
The sensor must directly contact the source, whether the water is running like a river or a tap or from a lake. This way, the sensor can accurately measure different parameters from the source.
2. Water quality detection
The sensor can start detecting water quality after successful deployment and installation. Note that every sensor cannot measure everything about water’s quality. Different sensors are used for different metrics and parameters. For example:
· To test the turbidity of the water, light is emitted into the water, and the sensor measures the amount of scattered light
· For pH testing, a glass electrode detects hydrogen ion concentration in the water
Chlorine ion detector can measure the chlorine ion content in water. The instrument has the advantages of accurate measurement, long life, simple operation and stable signal.
In this way, every sensor can take its designated water quality measurement.
3. Signal conversion
The data collected by the sensor is not presentable since it consists of raw signals. So, the next step after detecting quality is converting those raw data signals. Most sensors give analog signals, and we convert them into digital signals. It is because digital signals are much more efficient for further processing, display, and even data storage. The Analog-to-digital converter, also known as an ADC, takes the signal conversion step.
4. Signal processing
After converting the signals, they go through a signal-processing phase. This step involves the removal and filtering of the noise from overall data. Hence, it improves the overall signal quality as per the predefined standards. Since different sensors come with different qualities, the signal processing part may be done differently.
Some systems do this part with the sensor, known as onboard signal processing. Similarly, some systems use an external device for this purpose.
5. Data interpretation
Data display and interpretation is the final step in water quality testing after signal processing. Since we only have meaningful data now, this step converts that data into visible information like a graph. This is where any user can see the turbidity level, pH value, or oxygen concentration of water in an easily presentable way.
Some sensors come with a screen to show this data, while sometimes, we need to transmit this data to an external screen.
6. Maintenance
Maintenance and calibration are not done as frequently . However, it is an important part of the perfect working of these sensors. It is because, after continuous usage, the sensor may shift from its actual values. That’s where cleaning, part replacement, or recalibration with the system can help you regain the correct values. So, these sensors often go through periodic maintenance checks to ensure reliability.
Additional steps for smart systems
The abovementioned steps are the basics of a water quality sensor's working. However, today things are getting smarter with the applications of IoT. So, if you have a water quality sensor integrated with the smart IoT system, here are some additional steps involved in their working:
· Data transmission
Modern-day sensors can transmit real-time water quality testing results to remote systems or databases. It is usually done using cables, but wireless connections are also possible. Either way, this data transmission makes it possible to get water quality information without physically being near the sensor.
· Alerts
Some IoT systems come with a notification feature. Here users can set the parameters and their threshold values. So, the user gets a notification whenever the water quality crosses those threshold values. Hence, users can be sure they always use the best water quality.
· Data storage
It is important to store historical water quality testing data for analysis and record-keeping. So, sensor systems store periodic water quality testing data in local storage or databases.
Our top picks for water quality sensors
Here are our top 3 picks for water quality sensor you can choose from.
· pH Online Sensor
It is a temperature and PH sensor with smart functionality for online operation. It offers a complete range of pH measurements from 0 to 14 and accurate measurements from 0 to 65 degrees Celsius. With operational voltage as low as 9 volts, it is a very energy-efficient option.
COD/BOD sensor
Optical method online COD sensor is more economical and environmentally friendly than traditional chemical method. Small in size, easy to install, and can be used for continuous online water quality monitoring. Automatic compensation for turbidity disturbances, with automatic cleaning device, optional titanium alloy (corrosion resistant).
· Digital Nitrate Nitrogen Sensor
The 485-NO3 sensor can measure several things, including NO3-N, K+, Temperature, and pH. The nitrate nitrogen sensors can take measurements right at the basics and reduce your energy consumption and operational costs for aeration.
Conclusion
We cannot use any type of water for any use case. For example, water that contains biological organisms will not be healthy for consumption. Similarly, water with high nutrient or acidic concentrations may not be good for industrial use. So, checking the quality of water is essential, and that's where advanced technologies of water quality sensors work wonders.
Today we have sensors that can check various parameters about water quality. We can treat that water correctly with detailed data to make it safe and useful for the desired application.