In an era of increasing attention to the quality of resources consumed, Xiaomi’s water tester is becoming an indispensable gadget in the arsenal of any smart home owner.This compact device allows you to instantly assess the level of contamination of liquids, measuring the content of dissolved solids with high accuracy. Many users buy a device without fully understanding the principle of its operation, which often leads to false conclusions about the purity of tap water.
Proper use TDS-Meter requires understanding basic physical processes and following simple rules of operation. In this article, we will discuss in detail how to measure, interpret the data obtained and, most importantly, how to properly maintain the sensor so that it serves you for many years without losing the accuracy of measurements.
Principle of operation and technical specificities
The basis of the device is TDS-Total Dissolved Solids, which measures the electrical conductivity of a liquid, pure distilled water conducts virtually no electrical current, while the presence of salts, minerals and other impurities significantly increases its conductivity. Xiaomi’s gadget converts these readings into understandable numerical values expressed in milligrams per liter (mg/l) or ppm.
The body of the device is made of durable ABS-Plastics with moisture protection according to the standard IPX7, It allows you to wash it under a stream of water, but not completely immerse it for a long time, and it's got a highly sensitive titanium probe inside that is resistant to corrosion and provides stable readings even when used frequently. The screen is made using the technology of electronic ink paper, which makes it readable in any lighting and saves battery power.
It's important to understand that the device doesn't detect bacteria, viruses or organic compounds directly. It only responds to ionized particles. So a low TDS doesn't always mean that water is absolutely safe to drink, but it's guaranteed that there's no excess of hardness salts and heavy metals. This is often enough to measure the quality of life in a smart home in a comprehensive way.
Why can the testimony be downloaded?
Preparation for the first launch and calibration
Before active use, a number of preparatory steps must be performed. Although the Xiaomi TDS Pen comes from the factory with a basic calibration, a check is recommended to obtain reference accuracy. The package contains the device itself, a wet sponge protective cap (for storing the sensor), and a brief instruction.
☑️ Initial preparation of the device
The calibration process at home is possible, but requires a reference solution with a known TDS value, which is rare in regular stores. However, you can test the performance by measuring distilled water (the readings should be close to 0-10 ppm) and tap water (usually 100-300 ppm).
To clean the sensor before first use or after long downtime, use a soft cloth soaked in distilled water. Do not use aggressive chemicals or abrasives, as they can damage the sensitive coating of the electrodes. After wiping, be sure to let the device dry in air for a few minutes.
⚠️ Warning: Never store a device with a dry sensor for long periods.Always wear a protective cap with a wet sponge so that the electrodes don't dry out or oxidize.
Instructions: how to properly conduct measurements
The measurement process is as simple as possible for everyday use by the developers. To get a reliable result, put water in a clean container. If you're checking tap water, let it drain for 10-15 seconds to remove stagnant fluid in the pipes that may have increased turbidity or rust content.
Remove the protective cap and immerse the lower part of the device (touch zone) in water to a depth of 2-3 centimeters. Do not lower the device above the body section line, as the upper part is not sealed and moisture can enter, which will lead to breakage of electronics. Easy circular movement with your hand will help to remove air bubbles that sometimes stick to the electrodes and distort electrical conductivity.
Wait for the screen to stabilize, which usually takes 3 to 10 seconds, and the device automatically detects the temperature of the liquid and adjusts the readings, because the conductivity depends on the temperature of the medium, and after reading, shake off the excess water and wipe the body with a dry wipe.
Interpretation of results and table of values
When you get a number on the screen, many users are lost in guessing: is it good water or bad? TDS depends on the source of the water and your personal preferences. The World Health Organization does not set strict limits, but recommends certain ranges for drinking water.
Below is a table that helps decipher your tester’s readings:
| TDS range (ppm) | Quality assessment | Recommendations |
|---|---|---|
| 0 - 50 | Low salt content | Reverse osmosis water, distilled, drinkable, but may not taste good. |
| 50 - 150 | Optimal. | Perfect for drinking and cooking, a balance of minerals and purity. |
| 150 - 300 | High content | Typical of tap water, drinkable, but tastes good. |
| 300 - 500 | Very high. | The water is hard, it can scalp in the kettle, and filtration is recommended. |
| More than 500. | Unusable | High risk of contamination. Serious cleaning or replacement of the source is required. |
It is worth noting that for aquaristics, hydroponics or coffee preparation, water requirements can be drastically different, for example, for some plants, hydroponics requires strict nutrient control, where TDS is a key parameter, in such cases, focus on specific instructions for your activities, rather than general drinking water standards.
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The optimal TDS range for daily drinking is between 50 and 150 ppm, which corresponds to pure water with preserved natural minal balance.
Synchronization with the smartphone and ecosystem
Modern tester models, such as the Xiaomi Mi Water Quality Tester, often support connection to a smartphone via a Lightning or USB-C connector (for Android), which allows you not only to see current readings, but also to keep a history of measurements, plot the change in water quality over time.
To connect, you need to download the Mi Home app or the specialized application specified in the instructions (often Xiaomi Water Quality).The pairing process is simple: insert the tester into the smartphone connector, launch the application and follow the hints on the screen. The device does not require batteries when working with a smartphone, powered by it.
The application functionality allows:
- 📊 Maintain an automatic time- and geolocation-based measurement log.
- 📈 Analyze the dynamics of water quality changes (e.g., the efficiency of a new filter).
- 🔔 Receive notifications about the need to replace cartridges in filter systems (if integrated).
- 🌐 Share data with family members or send reports to service centers.
⚠️ Warning: When connecting to your smartphone, make sure the device connector is dry. Moisture entering the phone charging port can short-circuit and cause the gadget to fail.
Care, maintenance and replacement of elements
The durability of the device depends on how you care for it. The main enemy of the sensor is drying and mechanical damage. After each use, be sure to wipe the case and sensor with a soft cloth. Do not use solvents, gasoline or abrasive powders to clean.
If you notice that the readings have become unstable or the device has stopped turning on, check the power source. In standalone models, a standard battery like the CR2032 is used. Replacement is done by unscrewing the lid on the back. In smartphone models, no battery is required, but the phone connector itself must be serviceable.
Store the device should be exclusively in a protective cap. Inside the cap is a sponge, which is periodically (every 2-3 months) recommended to slightly moisten with distilled water, which will prevent the crystallization of salts on the electrodes and preserve their sensitivity.
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If the readings of the device began to strongly "swim" or stopped changing when immersed in different water, try to gently clean the sensor with a cotton swab dipped in a weak solution of citric acid, and then thoroughly wash with distilled water.