LS311 Multi-Parameter Water Quality Tester
For drinking water and seawater aquaculture
Measures 9 params: COD, TOC, TDS, salinity and more
Smart scoring for water quality as Excellent, Good, Average or Poor
Color display with intuitive color-coded results
Pen-style design — compact and easy to carry
Linshang LS311 is a multi-parameter water quality tester designed for household drinking water such as tap water, purified water, and groundwater. It is also suitable for seawater and aquaculture salinity testing.
The device uses UV absorbance to measure COD, TOC and UV275, and uses electrical conductivity to calculate TDS, electrical conductivity (EC), salinity (SAL), general hardness (GH) and specific gravity (S.G.). Linshang LS311 provides intelligent water-quality scoring, with backlight colors indicating four grades: Excellent, Good, Fair, and Poor. It also features automatic temperature compensation to ensure consistent repeatability and accuracy across different environments.
LS311 Water Quality Tester Featured Videos
Product application
Applications of the LS311 Water Quality Tester
Features
Fast testing for household drinking water
Simple operation—just press once to quickly determine whether the water meets national drinking-water safety standards.
Smart scoring system for clear water-quality assessment
The display automatically changes its backlight color according to the water-quality rating: Excellent, Good, Average, or Poor. The interface is intuitive and easy to understand.
Salinity, General Hardness & Specific Gravity measurement
By measuring electrical conductivity, LS311 accurately calculates salinity, general hardness, and specific gravity, helping users gain a complete understanding of the water’s condition.
Simultaneous measurement of 9 water-quality parameters
The instrument measures: SAL (salinity), GH (general hardness), S.G. (specific gravity), COD (chemical oxygen demand), TOC (total organic carbon), TDS (total dissolved solids), UV275 (ultraviolet absorption value), EC (electrical conductivity), Temperature — providing a full evaluation of water quality.
Indicator Analysis
Indicates the concentration of dissolved salts. Higher conductivity corresponds to higher salinity.
Determined by calcium (Ca²⁺) and magnesium (Mg²⁺) ion levels; more ions result in higher hardness.
Ratio of a solution’s density to water; useful in wastewater treatment and desalination to monitor concentration levels.
Reflects the level of organic pollution. Lower values indicate cleaner water.
A key indicator of organic contamination; higher TOC means more organic carbon present.
Represents the amount of dissolved inorganic salts, organic matter, and other solids.
Indicates how much organic matter absorbs UV light at 275 nm; higher values suggest higher organic content.
Measures concentration of charged ions such as dissolved salts, acids, or bases. Higher ion content results in higher conductivity.
Indicates the temperature of the water sample.
Multi-parameter scoring to avoid misjudgment
LS311 evaluates multiple parameters to give a more accurate and comprehensive rating for mineral and drinking water. A TDS pen alone can be misleading.
Pen-style design, compact and portable
The pen-style design makes the instrument small, lightweight, and easy to carry for on-the-go use.
Temperature compensation for accurate, stable results
Automatic temperature compensation ensures repeatability and accuracy across different environments, with long calibration intervals.
Indirect indication of residual chlorine
UV275 readings can indirectly reflect residual chlorine levels—higher chlorine typically results in higher UV275 values.
High-sensitivity probe for more accurate readings
High-precision temperature sensor for precise measurement
Probe waterproof rating up to IP67
Video
LS311 Water Quality Tester Operation video
Parameter
| Parameter | Value |
|---|---|
| Measurement Object | Tap water, purified water, bottled water, ground water, surface water (non-sewage) seawater and aquaculture |
| Measurement parameters | COD(Chemical Oxygen Demand)、TOC(Total Organic Carbon) 、UV275(Ultraviolet Absorption Value) TDS(Total Dissolved Solids)、EC(Electrical conductivity)、SAL(Salinity) GH(General Hardness)、S.G.(Specific Gravity)、T(Temperature) |
| Measurement Range | COD(0-100mg/L)、TOC(0-100mg/L) 、UV275(0-1.0au/cm)、TDS(0-2000ppm) EC(0-4000us/cm)、SAL(0-26%)、GH(0-1000ppm)、S.G.(0.9800-1.2000)、T(0-50℃) |
| Resolution | COD(0.01mg/L)、TOC(0.01mg/L) 、UV275(0.001au/cm)、TDS(1ppm) EC(1us/cm)、SAL(0.01%)、GH(1ppm)、S.G.(0.0001)、T(0.1℃) |
| Accuracy(H is the standard value) | COD：0-5mg/L：±0.5mg/L；5-100mg/L：±10%H TOC：0-5mg/L：±0.5mg/L；5-100mg/L：±10%H UV275: 0-0.1au/cm：±0.01au/cm；0.1-1.0au/cm：±10%H TDS： 0-100ppm：±5ppm；100-2000ppm：±5%H EC：0-200us/cm：±10us/cm；200-4000us/cm：±5%H SAL：0-5%：±0.25%；5-15%：±5%H；15-26%:±10%H T：±2℃ |
| Display | 240*135 1.14 inch TFT color screen |
| Power Supply | 2 AAA alkaline dry batteries |
| Size | 157*37*14mm |
| Weight | About68g |
| Working Temperature Range | 0~50℃ |
| Storage Temperature Range | -10~60℃，0~85%RH（no condensation） |
| Supply Voltage | DC3V |
| Operating Current | 20mA |
| Operating Power Consumption | 60mW |
Qualifications and Standards
LS311 Water Quality Tester meets the following standards:
GB5749-2022 Sanitary Standard for Drinking Water
GBT5750-2023 Standard Test Methods for Drinking Water
JJG 821-2005 Total organic carbon analyzer test procedure
JJG 376-2007 Conductivity meter testing procedures
JJG 761-2016 Verification Regulation of Electrode Salinometer
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