About TDS pen:

   TDS is the abbreviation of total dissolved solids in Chinese, and is measured in milligrams per liter (mg/L), indicating that 1 liter of water contains milligrams of dissolved solids.
   TDS concept is an imported product, which is widely used in the water treatment field in the United States and Taiwan. The measurement tool of TDS value is usually TDS pen, and its measurement principle is actually indirectly reflecting TDS value by measuring the conductivity of water. In the physical sense, the more solutes in water, the greater the TDS value of water, the better the conductivity of water, and the greater its conductivity value.
   Generally speaking, TDS value represents the content of dissolved impurities in water. The larger the TDS value, the larger the impurity content in the water.

Factors influencing TDS value test:

Water temperature: TDS pen cannot be used to measure high temperature water (for example, hot water)
Flow rate of water: the TDS pen cannot be used to measure shaking water

Product instructions:

Remove the pen cover and turn ON the switch.
Put the pen into the test solution, the solution height should not exceed 2cm;
Stir the pen in the solution. When the reading is stable (2-6 seconds), the TDS value will be displayed on the screen. Then press the HOLD key to lock the value.
Wipe the water on the end of the pen, clean it with clean water and cover it back.
Use caution: avoid soaking the TDS pen all over the body into the water, avoid direct sunlight, stay away from high temperature, avoid impact pressure and crash.

Product range:

Test whether the water quality of tap water, purified water and mineral water meets the drinking water standard formulated by the state: under 300PPM of tap water, under 50PPM of pure water (national standard), between 100ppm and 200PPM of mineral water.

The specification parameters of the test pen are as follows:

Lightweight pocket - weighing 28 grams - is the smallest and lightest portable TDS instrument on the market today, measuring 14.2 by 2.3 by 1.3 (CM).
Measurement range is wide - be able to measure 1-9990ppm (display above 999PPM, value X10).
Application temperature ranges from 0 to 50 degrees and can be stored at -30 degrees.
Liquid crystal display window -- big screen liquid crystal display waterproof design, convenient to watch, durable
Battery life long - use CR1620 3V battery 2, can use more than 3 years, 10 minutes not operating automatic shutdown function, save battery.
Design is reasonable - the tip of the pen can be inserted directly into the water solution to measure, and the pen cover can also be used as a container of the water solution, which is very convenient.
Measurement is fast - due to exquisite bare sensor elements, 5 seconds can complete a measurement.
Accuracy - 1% error, high accuracy of titanium probes, free from magnetic interference in water.
Automatic temperature compensation - a value that can be automatically converted to 25 degrees.