How to use it TDS-Xiaomi metro: full instruction with expert advice

TDS-Xiaomi’s meter is a compact gadget that helps you measure water quality right in your home, and it can measure Total Dissolved Solids, which is especially useful for checking filters, aquariums, or even tap water. But how do you use this device to get accurate data? In this article, we'll go through all the nuances, from the preparation of the device to the decoding of the results.

Models of Mi TDS Pen and ClearGrass (branded Xiaomi) work on a similar principle, but have slight differences in calibration and range of measurements. We will look at the universal rules, and also point out the features of specific devices. TDS-Meter or long ago you use it, but doubt the accuracy of the readings - this instruction is for you.

What is it? TDS Why do you want to measure this indicator?

abbreviation TDS (Total Dissolved Solids, which is the total amount of dissolved solids in water, includes salts, minerals, metals and other impurities that are not visible to the naked eye, but affect the taste, smell and safety of water. TDS in ppm (parts per million, parts per million) or mg/L.

Why does it matter?

• 💧 Controlling filters: If your water filter is no longer working effectively, TDS-The meter will show it immediately - the level of mineralization will not change.
• 🐟 Aquarium: Different fish species require water with a certain level of hardness, such as discus prefer soft water (50-150 ppm) and African cichlids prefer hard water (200-400 ppm).
• ☕ Drinking: Coffee and tea are ideal for water with TDS 50-150 ppm. Too high mineralization will spoil the taste.
• 🏠 Domestic use: Water with TDS above 500 ppm can leave scale on the kettle and washing machine, reducing their service life.

TDS-Xiaomi does not define the specific composition of the impurities (for example, does not distinguish calcium from lead), but gives an overall picture. For detailed analysis, laboratory tests will be required.

Complementation and appearance TDS-Xiaomi

In the box with TDS-Xiaomi metro (models Mi) TDS Pen or ClearGrass, you will find it:

• 📱 The device itself in a protective case (sometimes the case is sold separately).
• 📄 Instructions in Chinese/English (Russian version is rare).
• 🔋 Battery CR2032 (In some models, it has already been installed).
• 💧 Calibration solution (not in all sets, often sold separately).

The exterior of the device is like a ballpoint pen with a display.

• 🔄 Button ON/OFF (switch on/off, sometimes combined with a calibration button).
• 📊 Screen (shows value) TDS, water temperature and battery charge indicator).
• 🔋 Battery compartment (usually closed with a screw or latch).
• 💧 Sensor (metal tip that is immersed in water).

Note the measurement range: most Xiaomi models have 0-9990 ppm, but budget versions may be limited to 0-1999 ppm.

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If the kit does not contain a calibration solution, it can be purchased separately (for example, a standard solution of 342 ppm for household products). TDS-Meters) or use distilled water (0 ppm) to verify accuracy.

Preparation TDS-metre to first use

Before the first turn on, follow a few simple steps:

1. Install the battery (if not installed). To do this, unscrew the compartment on the back of the device and insert the element. CR2032, polarize.
2. Wash the sensor with distilled or filtered water to remove any possible contaminants from the plant.
3. Check leakproofness: Make sure the battery compartment cover is tightly closed, otherwise moisture could damage the electronics.

Now you can turn the device on with a button. ON/OFF. There should be a sign on the screen. TDS And zero readings. If the display doesn't respond:

• 🔋 Check the battery (it may be discharged or installed incorrectly).
• 💧 Make sure the sensor is dry – moisture on the contacts can block the switching on.
• 🔄 Try holding the switch on 3-5 seconds to reset.

How to measure correctly TDS tap and filtered water

To get accurate data, follow this algorithm:

1. Put water in a clean glass (preferably glass or plastic without drawings), a volume of at least 100 ml, so that the sensor is fully immersed.
2. Remove the air bubbles: stir the water gently or wait 1-2 minutes. Bubbles can distort readings.
3. Immerse the sensor in water to a depth of 2-3 cm (without touching the bottom or walls of the glass). TDS.
4. Wait 10 to 15 seconds for the readings to stabilize, and if the numbers keep changing, the water isn't uniform enough.
5. Record the result and compare with the standards (see the table below).

Important nuances:

• 🚰 For tap water, measure TDS directly from the tap, draining the water for 1-2 minutes (to avoid stagnation in the pipes).
• 💧 For filtered water, take a sample immediately after the filter, not from the storage tank (the water may become contaminated there for a second time).
• ❄️ The water temperature should be in the range of 0-50°C. Too hot or cold water distorts results.

Critical error: Many users immerse the sensor in a stream of water (for example, under a tap), which leads to unstable readings due to turbulence. TDS stationary!

Sizing TDS-Xiaomi meter: when and how to conduct

Sizing is required if:

• 📉 Distilled water (0 ppm) readings are more than zero. ±5 ppm.
• 🔄 You have not calibrated the device for a long time (recommended every 2-3 months with active use).
• 💧 After falling or mechanically impacting the sensor.

The calibration will require a standard solution (usually 342 ppm or 1413 ppm) if not available, distilled water (0 ppm) can be used, but this is less accurate.

Step-by-step:

1. Turn the device on and immerse the sensor in the calibration solution.
2. Hold the button. ON/OFF (or a special calibration button, if any, during the 5–10 seconds until the screen has an inscription CAL or SET.
3. Wait for the stabilization of the readings (they should coincide with the specified value of the solution, for example, 342 ppm).
4. Press the button again to save the settings. The device will automatically turn off.

If the calibration fails:

• 🔋 Check battery power - a discharged battery can knock down settings.
• 💧 Make sure the solution is fresh (the shelf life of the standard solution is 1 year after opening).
• 🔄 Try resetting the device to factory settings (hold the switch on button for 15 seconds).

Common errors in the use of TDS-square

Even experienced users sometimes make mistakes that distort the results, and here are the most common ones:

• 🧴 Measurement in dirty dishes: Residues of detergent or fat on glass walls may increase TDS 10 to 50 ppm. Always use clean dishes.
• 🌡️ Ignoring temperature: The device automatically compensates for the temperature, but if the water is too hot (>50°C) or cold (<0°C), the readings will be inaccurate.
• 💦 Sensor immersion in flow: As mentioned, turbulence distorts data. Measure only in a stationary container.
• 🔋 Battery discharge: At low charge, the device may show inflated values or shut down during measurement.
• 🧂 Contact with salt or sugar: If the sensor accidentally touches salt crystals, it must be thoroughly washed - otherwise the readings will be inflated.

Another common problem is condensation inside the case, and if the device was stored in a wet room (like a bathroom), moisture can get in and cause contacts to corrosion.

• Keep it. TDS-meter in a dry place (for example, in a case with silica gel).
• After use, wipe the sensor with a dry wipe.
• Do not leave the device in water for a long time (maximum 5 minutes of continuous measurement).

⚠️ Note: If there are symbols on the screen LO BAT or ERR, Replace the battery immediately, and use a battery-discharged device may cause calibration failure!

Care for TDS-Metro: How to extend the service life

With care TDS-Xiaomi will last 2-3 years. Here are the basic rules of care:

• 🧼 Clean the sensor: After each use, wash the tip with distilled water. Once a month, clean it with a soft brush soaked in a weak acetic solution (1 part vinegar to 3 parts water).
• 🔋 Battery: If you don’t use the device for more than a month, remove the battery to avoid contact oxidation.
• 🌡️ Storage: Optimal temperature - 10–30°C. Avoid direct sunlight and humidity above 80%.
• 🚫 Do not drop the device - the sensor is fragile and can crack. Do not plunge the body deeper than 5 cm (risk of water getting inside). Do not use abrasives for cleaning (they scratch the sensor).

If the sensor is still contaminated by plaque (for example, from hard water), try the following method:

1. Prepare a solution of citric acid (1 teaspoon per 100 ml of warm water).
2. Load the sensor for 10-15 minutes.
3. Clean gently with a soft toothbrush.
4. Wash thoroughly with distilled water and dry.

⚠️ Warning: Do not use alcohol, acetone or other aggressive solvents for cleaning – they can damage the protective coating of the sensor!

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Regular cleaning of the sensor and proper storage increase the accuracy of measurements by 20-30% and extend the service life of the device by 1.5-2 times.

FAQ: Answers to Frequent Questions about TDS-Xiaomi meters