VVNA | How to Judge Water Quality Using a Water Quality Tester? Interpretation of Key Indicators and Practical Operation Guide

I. Measuring pH Value: Using a Portable pH Meter to Check "Acid-Base Balance"

The pH value of water is like a "balance" that maintains water quality stability. The national standard clearly stipulates that the pH value of drinking water must be between 6.5 and 8.5 — this is the optimal range for ensuring human comfort and pipeline safety. Acidic water (pH ＜ 6.5) will slowly corrode metal pipelines, leading to the leaching of substances such as lead and iron; alkaline water (pH ＞ 8.5) may make the skin feel dry and tight after washing, and will also affect the foaming effect of detergents. At this time, a portable pH meter can be of great use: whether for household self-inspection of drinking water or field screening of source water, you only need to take a small amount of water sample, put the instrument probe into the water, and the accurate pH value can be read within 30 seconds. This allows you to quickly judge whether the acid-base balance of the water is "qualified", setting the first barrier for healthy drinking water.

II. Measuring Dissolved Oxygen: Using a Portable Dissolved Oxygen Meter to Check "Vitality"

Dissolved oxygen (DO) is the "vitality indicator" of water bodies. It not only supports the respiration of aquatic organisms such as fish and shrimp, but also reflects whether the water quality is polluted — the dissolved oxygen in normal natural water bodies should be ≥ 5 mg/L. If it is lower than this value, it indicates that the water body may be polluted by organic matter (such as the inflow of domestic sewage), and aquatic organisms will face the risk of suffocation. In actual detection, the advantages of portable dissolved oxygen meters are particularly obvious: aquaculture farmers can use them to detect fish pond water at any time to avoid fish and shrimp deaths caused by a sudden drop in dissolved oxygen; environmental protection personnel can also use them to quickly capture abnormal DO points during river inspections, timely track pollution sources (such as illegal discharge of industrial wastewater), and provide real-time data support for water ecosystem protection.

III. Measuring COD: Using a Portable COD Meter to Judge "Organic Pollution"

COD (Chemical Oxygen Demand) is a hidden "pollution code" in water, representing the total amount of oxidizable organic matter in the water body — detergents in domestic sewage, chemical agents in industrial wastewater, and straw humus in agricultural runoff will all push up the COD value. When COD exceeds the corresponding water body standard (e.g., drinking water COD must be ≤ 3 mg/L, Class Ⅲ surface water COD ≤ 20 mg/L), it means that organic matter will decompose in the water, consuming a large amount of oxygen, and even producing toxic metabolites. The portable COD meter can break the lag of laboratory detection: after sampling at enterprise discharge outlets, environmental inspection personnel do not need to take the samples back to the laboratory. Instead, they can complete the detection on-site with the meter and obtain the COD value within 15 minutes, quickly judging whether the wastewater is discharged exceeding the standard, and blocking the spread of organic pollution from the source.

IV. Measuring Ammonia Nitrogen: Using a Portable Ammonia Nitrogen Meter to Identify "Eutrophication Hidden Dangers"

Ammonia nitrogen is the behind-the-scenes culprit of water bodies "turning green and stinking", mainly derived from urea in domestic sewage, industrial wastewater (such as wastewater from chemical fertilizer plants and breeding farms), and agricultural chemical fertilizer leakage. When the ammonia nitrogen content exceeds the standard, it will not only directly poison fish and shrimp (e.g., ammonia nitrogen ＞ 0.5 mg/L is irritating to fish), but also be converted into nitrates under the action of microorganisms, causing water eutrophication, making rivers and lakes covered with green algae, and forming "dead zones". The portable ammonia nitrogen meter precisely meets the needs of on-site screening: at key points such as irrigation wells around farmland and river estuaries, it can be used to detect water samples, instantly find abnormal ammonia nitrogen levels, and take control measures in advance (such as restricting chemical fertilizer use and rectifying polluting enterprises) to avoid damage to the water ecosystem.

V. Measuring Heavy Metals: Using a Portable Heavy Metal Detector to Uncover "Hidden Killers"

Heavy metals are the most dangerous "hidden lurkers" in drinking water. Even at extremely low concentrations (e.g., lead ≤ 0.01 mg/L, mercury ≤ 0.001 mg/L), elements such as lead, mercury, cadmium, and chromium will accumulate in the human body after long-term consumption, damaging the liver, kidneys, and even the nervous system. These heavy metals mostly come from industrial wastewater (such as electroplating and smelting wastewater) and the corrosion of aging pipelines, which are completely invisible to the naked eye. The portable heavy metal detector can make these "invisible killers" visible: families can regularly use it to detect tap water from faucets to check for heavy metal leaching in pipelines; during field adventures, it can also be used to quickly detect mountain springs and streams to judge whether there is heavy metal pollution, ensuring drinking safety. Through specific reagent reactions and spectral analysis, it can accurately measure the content of multiple heavy metals within 10 minutes, building the last line of defense for health.

In fact, water quality is not "invisible and intangible". With the help of these portable detection instruments, every indicator — from the acid-base balance of pH value to the hidden risks of heavy metals — can be converted into intuitive data. Whether for daily drinking water self-inspection or outdoor water source screening, as long as you master the detection methods of these key indicators, you can actively safeguard the water quality safety around you.

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