In modern life, tap water quality is often questionable, and a simple visual inspection will not help. Xiaomi TDS-meter is an indispensable gadget for those who monitor their health and the condition of household appliances. This compact device is able to determine the level of dissolved solids in seconds, which is critical for users of reverse osmosis filters and air humidifiers.
Many Mijia smart device owners underestimate the capabilities of this small device, using it only for initial testing. However, a proper understanding of the readings and regular calibration allows you to significantly extend the life of kettles, coffee machines and steam generators. In this article, we will examine all the nuances of operation, from the first turn on to the interpretation of complex data.
Operating principle and device design
The basis of the device is a high-precision sensor that measures the electrical conductivity of a liquid. The more salts, minerals and metals dissolved in water, the better it conducts electric current. TDS Pen converts this data into understandable numerical values by displaying it on the built-in OLED-display.
The device is structurally made of durable plastic with protection from moisture according to the IPX6 standard. This means that it is not afraid of an accidental fall into a glass or sink. The upper part is equipped with a removable cap, which also acts as a stand, allowing you to steadily place the device on the table during measurements.
⚠️ Warning: Do not lower the device into water deeper than the mark MAX, If you get moisture into the battery compartment or onto the electronic circuit board, it'll knock the sensor out of order.
Power is supplied by two standard batteries, such as LR44 (or AG13), which come with minimal energy consumption, one charge lasts for several months of active use, and automatically shutting down after 10 minutes of inactivity helps to save the life of the batteries.
Technical characteristics of the sensor
First start and preparation for work
Before you start using it, you need to remove the device from the package and remove the protective film from the display. At the bottom of the case is a battery compartment. Unscrew the lid counterclockwise, install the power cells while observing polarity, and tightly twist the lid back.
Once the power is installed, the screen will light up, showing current values. If you see flashing symbols or readings that are very different from zero in the air, this may indicate battery discharge or contamination of contacts. Make sure that the sensor contacts are clean and dry before diving.
For initial inspection, it is recommended to dip the device in a glass of pure bottled water. The readings should be low, usually in the range of 0-50 ppm. If the device shows values above 100 ppm in distilled water, calibration or replacement of batteries may be required.
☑️ Testing of device readiness
Step-by-step: how to make measurements
The measurement process is as simple as possible and requires no special skills, but following the sequence of actions ensures the accuracy of the result. First, remove the protective cap and rinse the sensor in the water you plan to test to remove the residues of previous solutions.
Immerse the lower part of the device in a container with liquid to a depth 2-3 Don't touch the glass and bottom, hold it. TDS-You can use a meter that's vertical in the center of the tank, and if you mix it with the device, you can remove the air bubbles that can distort the readings.
Wait for the numbers to stabilize on the screen. It usually takes 3 to 5 seconds. When the value stops changing, you can take the device out. If you're syncing with your smartphone, the data will automatically be saved in the Mijia app.
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For the most accurate data, measure water at room temperature (25°C.) Hot or ice water can give an error due to changes in electrical conductivity of the medium.
After the procedure is complete, be sure to shake off the remaining water and wipe the sensor with a soft napkin. Store the device in a dry place with a protective cap on it. Regular care of the sensor prevents the formation of scale, which over time reduces the sensitivity of measurements.
Indicators and standard table
Understanding what the numbers on the screen mean is a key skill. The unit of measurement is ppm, which means the number of particles per million. The higher the value, the more impurities there are in the water.
For drinking water, the optimal range is 50 to 250 ppm. Water with values above 500 ppm is considered hard and can be unpleasant to taste, and also form scale in kettles. Values above 1000 ppm indicate severe pollution, such water is not recommended to drink without filtration.
| Range (ppm) | Water quality | Recommendation |
|---|---|---|
| 0 - 50 | Perfect (after reverse osmosis) | Suitable for drinking and engineering |
| 50 - 150 | Good (bottled) | Optimal for daily use |
| 150 - 300 | Normal (water supply) | Requires filtration for drinking |
| 300 - 500 | Hard. Hard. | Not recommended for drinking, only for household needs |
| 500+ | Contaminated. | Unusable for use without cleaning |
It is important to note that TDS-The meter does not detect bacteria, viruses or organic contaminants, it only measures the total dissolved solids. TDS It does not guarantee complete biosafety, although it is often correlated with a high degree of purification.
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A low TDS score (less than 50 ppm) indicates a high degree of water purification characteristic of reverse osmosis systems, but does not confirm the absence of bacteria.
Synchronization with the smartphone and ecosystem
One of the key features of the device is the ability to connect to the Mijia app, which allows you to keep a measurement history, track the effectiveness of filters and share data with family members. To connect, turn on Bluetooth on your smartphone and open the application.
Press the button on the body TDS-In the app, select Add Device and follow the instructions on the screen. Once paired successfully, all measurements will automatically be stored in the cloud, creating detailed statistics on the water quality in your home.
The app’s automatic calibration feature makes it much easier to maintain the appliance, the system will tell you when to calibrate the device or replace the batteries, and the app also provides detailed articles and tips on improving water quality.
Calibration and maintenance of the device
Over time, the sensor may lose accuracy, especially when used frequently or in contact with aggressive environments. Calibration is the process of adjusting the instrument to reference values. For the Xiaomi TDS, this procedure is performed using a special calibration solution (usually 342 ppm or 1000 ppm).
To calibrate the device, immerse it in a solution of known concentration. If the readings are different from the reference, start the calibration process through the Mijia application or use a combination of buttons (if provided by the model), the device will automatically adjust the coefficients.
⚠️ Warning: Never use ordinary tap water for calibration, as its composition is unstable.
Regular maintenance involves wiping the sensor with a soft cloth soaked in distilled water.Do not use abrasive materials or chemical solvents that can damage the electrode coating. Store the appliance in a dry place at room temperature.
Frequent errors and troubleshooting
Users often experience situations where the device shows floating values or doesn't turn on. Most of the time, the problem is with the batteries being discharged or the contacts oxidizing. Replacing the batteries with fresh alkaline batteries often solves the problem.
Another common mistake is to measure the flowing tap water without first draining it, and the water in the pipes can stagnate, changing its properties, and always let the water drain 10-15 seconds before sampling for analysis.
If the device is not in use for a long time, remove the batteries to avoid leakage and corrosion of the contacts. Periodically check the integrity of the case and the absence of cracks through which moisture can penetrate into the electronics.