Portable Digital ATC PH Meter 0.00~14.00 Water Fish Tank Monitor Water Quality Solution Analyze r LCD Glass Electrode
How to use:1. 1 bag 6.86 PH buffer powder  needs 250ml water(Distilled water, Pure water, water with PH value neutral in room temperature), then shake it gently, then use the pen to test it. If it display 6.8, then the pen is good to use.2. If not, please use the screw to calibrate it ( The hole in the back ) , until the value is 6.83. If use 4.0 powder to calibrate, the test result need to be 4.0, and the pen need to stay in the water Note:The PH meter need to be recalibrated, when:1. the PH meter has been used or placed for a long time2. the PH meter has been used frequently3. High accuracy is needed How to use Take the electrode cover off before use Press the ON/OFF key, place the electrode into the solution to be tested;After the value is stable, press the HOLD button to take out and reading;After finished, press the ON/OFF key, wipe the electrode clean, and insert the electrode protection Cover;

TDS Water Quality Testing Pen Drinking Water Detector TDS Water Tester PPMTDS-3 Handheld Meter With Carrying Case is a tool to measure Total Dissolved Solids (TDS) or the total amount of mobile charged ions, including minerals, salts or metals dissolved in a given volume of water. It is very portable, reliable and accurate in testing water and other solutions due to its advanced microprocessor technology. This handheld meter is ideal for all water purification applications, wastewater regulation, aquaculture, hydroponics, and colloidal silver. Perfect for both consumer or commercial use.TDS, which is based on conductivity, is expressed in parts per million (ppm) or milligrams per liter(mg/L). TDS includes any conductive inorganic element present other than the pure water molecules (H2O) and suspended solids. The higher the TDS level in water, the greater the probability of harmful contaminants that can pose health risks or hinder the absorption of water. 
* The U.S. EPA’s Maximum Contaminant Level of TDS for human consumption is 500 ppm.

Features & Benefits:

• Efficient and accurate.
• Saves measurements for convenient reading and recording.
• Conserves battery, shuts off automatically after 10 minutes of non-use to conserve batteries.
• Measurement Range: 0-9990 ppm. From 0-999 ppm, the resolution is in increments of 1ppm. From 1000 to 9990 ppm, the resolution is in increments of 10 ppm, indicated by a blinking 'x10' image.
• Built-in digital thermometer.
• Large and easy-to-read LCD screen display.
• Calibrated with a 342 ppm NaCl solution.
• Also available in "x10" mode: reads in increments only of 10 ppm (0-9990 ppm).

TDS Scale
* This is a typical TDS, Total Dissolved Solids Scale , what you can expect your water to be.

SpecificationsModel: HMD-TDS-3Manufacturer ID: HMD-TDS-3Dimensions(inch/es): 6.1 x 1.25 x 1 inchesTDS Range: 0 - 9990 ppm (mg/L)Temperature Range: 0 - 80° CTemperature Resolution: 0.1° C(Celsius only)Resolution: 0-999: 1 ppm; 1000-9990: 10 ppm (indicated by a 'x10' icon)Accuracy:+/- 2%EC-to-TDS Conversion Factor: NaCl (avg. 0.5)ATC: Built-in sensor for Automatic Temperature Compensation of 1° to 50° Celsius(33° to 122° Fahrenheit)Power source: 2 x 1.5V button cell batteries  (LR44 or equivalent)Battery life: 1000 hours of usageWeight : 56.7g (2 oz)