Pen-type TDS Meter - (Small Volume, Fast Measurement Speed with Automatic Temperature Compensation)
This product has the following features:
* Auto Shutdown - Auto Shutdown feature, the computer will automatically turn off after 10 minutes.
* Reasonable design -- the pen-tip electrode can be directly inserted into the drinking bottle mouth to measure, and the pen cap can be used as the container for the measured liquid, making it extremely convenient to use;
* Measurement speed -- thanks to the compact and bare sensor element, a measurement can be completed in 2-6 seconds.
* Easy to Clean -- The electrode sleeve can be removed, making it convenient to clean the probe and the sleeve. (The probe is made of titanium gold).
Main Technical Parameters:
* Measurement Range: 0～9990mg/l (PPM);
Resolution: 1 mg/L
Accuracy: ±2% (F.S)
* Power Supply: 2×3V (CR2032 Battery)
* Automatic Temperature Compensation: The display value can be automatically converted to the value at 25°C.
* Operating Temperature: 0~50°C
* Environmental relative humidity: <85%
*Application scope: Pure water production and drinking, electroplating liquid, boiler water, aquarium water, swimming pool water purity, photographic developing liquid, well water, deep well water, laboratory, aquaculture, food processing, family, office, physical and chemical teaching, ionized water cosmetics, municipal water supply, travel health care.

The biggest selling point of this TDS pen: the water testing probe is made of titanium alloy, the biggest difference from the stainless steel probe: magnetic interference in water can affect the accuracy of water value measurement, the titanium alloy probe significantly reduces the probability of such magnetic interference. The leather case type TDS pen is the earliest first-generation water testing tool, and the new generation of water testing tools that have replaced it are TDS pens with titanium alloy probes, which are also much lighter and more beautiful in appearance than the former, with small volume (only 28 grams), high measurement accuracy, and convenient to carry features.

● Compact and Pocket-sized → Weighs 28 grams, the smallest and lightest portable TDS instrument on the market today, measures 14.2cm long by 2.3cm wide by 1.3cm thick.
● Measurement range wide → able to measure 1-9999 PPM.
● Wide operating temperature range → Operates at 0-50°C, storage at -30°C.
● LCD display window → large-screen LCD display with waterproof design, convenient for viewing, durable and long-lasting
● Long battery life → Uses 2 pieces of CR1620 3V batteries, which can last over 3 years. The device will automatically turn off after 10 minutes of inactivity to save battery power.
● Reasonable design → The pen-tip electrode can be directly inserted into the measured aqueous solution for measurement, and the pen casing can also be used as a container for the measured aqueous solution, which is extremely convenient.
● Measurement speed → Due to the delicate and bare sensor element, it can complete a measurement in 5 seconds.
● High accuracy → ±1% error, titanium alloy probe for measuring water has high precision and is immune to magnetic interference in water.
● Automatic temperature compensation → can automatically convert the display value to the value at 25 degrees.

TDSTDS is the abbreviation for "total dissolved solids" in English, and its Chinese translation is "总溶解固体". It indicates the amount of milligrams of dissolved solid matter per liter of water, which shows the concentration of dissolved solids in the water.
The concept of TDS is a foreign import, widely used in the water treatment fields of the United States and Taiwan. The measurement tool for TDS values is generally an TDS pen, and its measurement principle is actually to measure the electrical conductivity of water to indirectly reflect the TDS value. In physical terms, the more dissolved solids in water, the larger the TDS value of the water, and the better the conductivity of the water, the larger the electrical conductivity value.
In layman's terms: The TDS value represents the content of dissolved impurities in water. The higher the TDS value, the greater the content of impurities in the water, and vice versa, the smaller the content of impurities.

Water temperature: The TDS pen is not suitable for measuring high-temperature water (e.g., boiling water).
The flow rate of water: A TDS pen cannot be used to measure water with significant agitation.

Remove the pen cap and turn on the ON switch.
Insert the pen into the test solution, and the height of the solution should not exceed 2cm.
Stir the pen in the solution, and after the reading stabilizes (2-6 seconds), the TDS value will be displayed on the screen. At this time, press the HOLD button to lock the value.
After use, wipe the water off the tip of the pen, clean it with pure water, and then cover the pen cap back on.
Use caution: Avoid immersing the TDS pen completely in water, avoid direct sunlight, stay away from high temperatures, and avoid impact, pressure, and falling.

To detect the quality of tap water, pure water, and mineral water to see if they meet the national drinking water standards: tap water should be below 300 PPM, pure water should be below 50 PPM (national standards), and mineral water should be between 100-200 PPM.