What is COD, BOD, and TSS?

Yes, PROBEST water quality sensors require regular calibration. The calibration cycle varies by sensor type. It is generally recommended to calibrate every two weeks or based on usage frequency to ensure data accuracy.

Answer: All genuine, high-quality PROBEST online digital water quality monitoring sensors meet the IP68 waterproof standard.
They are designed for long-term underwater operation and can function reliably at depths up to 10 meters.

All PROBEST water monitoring analysis sensors are with the RS485 (MODBUS-RTU) signal output.
This industry-standard, stable transmission protocol offers strong compatibility and enables seamless integration with various monitoring systems such as SCADA systems and smart water management platforms.
No additional conversion modules are required; simply connect according to the standard wiring sequence to achieve real-time data upload.

Answer: By utilizing the fluorescence excitation properties of phycocyanin in cyanobacteria, a specific wavelength light beam excites the phycocyanin.
The intensity of the emitted fluorescence is then measured to accurately calculate the cyanobacteria concentration.

Water quality analysis is the process of using specialized methods to test physical, chemical, and biological indicators in water to assess whether the water meets usage standards (such as for drinking, industrial, agricultural, etc.).

Interrelationships Among Water Testing Parameters in Environmental Monitoring

Relationship Between Hexavalent Chromium and Total Chromium

 

Chromium in water typically exists as trivalent and hexavalent forms, which can convert under certain conditions. Total chromium is the sum of trivalent and hexavalent chromium. Therefore, for the same water sample, the following logical relationship holds:

 

Total Chromium > Hexavalent Chromium

 

Relationship Between Sulfides and Heavy Metals

 

In the same water sample, high sulfide concentrations correlate with lower concentrations of heavy metals (Cu, Pb, Zn, Cd, etc.). However, this relationship may not hold if heavy metals exist in complexed forms.

 

Relationship Between Total Bacteria Count, Coliform Bacteria, and Fecal Coliform Bacteria

 

Coliform bacteria represent only one population among bacterial species and have limited contamination pathways. Long-term testing indicates that samples detecting coliform bacteria also detect total bacteria count. Conversely, samples with high total bacteria counts do not necessarily detect total coliform bacteria. Fecal coliform bacteria belong to the total coliform group and are detected at 44.5°C, which is higher than the 37°C detection temperature for total coliform bacteria. Therefore, fecal coliform values are typically lower than total coliform values, i.e., fecal coliform value < total coliform value.

Interrelationships Among Water Quality Parameters in Environmental Monitoring

Relationship Between Nitrite Nitrogen and Total Nitrogen

 

Nitrogen primarily exists in aquatic environments as nitrate, nitrite, ammonia, and organic nitrogen. Therefore, total nitrogen should equal the sum of nitrite nitrogen and organic nitrogen. For the same water sample, the following logical relationships hold:

 

Total Nitrogen > Ammonia Nitrogen Total Nitrogen > Sum of Ammonia Nitrogen, Nitrate Nitrogen, and Nitrite Nitrogen

 

Interrelationships Among Water Quality Parameters in Environmental Monitoring

Relationship Between Water Temperature and Dissolved Oxygen

 

The distribution and variation of dissolved oxygen in water result from the combined influence of temperature, biological activity, chemical processes, and various physical phenomena. Overall, it is primarily controlled by water temperature, exhibiting pronounced seasonal fluctuations. Dissolved oxygen levels in water show a negative correlation with temperature and generally should not exceed the saturation level corresponding to the prevailing water temperature.

 

Interrelationships Among Water Quality Parameters in Environmental Monitoring

Relationship Between Nitrogen Compounds and Dissolved Oxygen

 

Since the forms of nitrogen present in the environment change with variations in environmental conditions, particularly influenced by the concentration of dissolved oxygen in water bodies, nitrate nitrogen and ammonia nitrogen cannot be high simultaneously. Generally, in water bodies with high dissolved oxygen, the concentration of nitrate nitrogen is higher than that of ammonia nitrogen, and conversely, the concentration of ammonia nitrogen is higher than that of nitrate nitrogen. Nitrite nitrogen concentrations show no significant correlation with these parameters.

Interrelationships Among Water Testing Parameters in Environmental Monitoring

Relationship Between Petroleum Hydrocarbons and CODcr

 

Petroleum hydrocarbons are organic pollutants that can be oxidized by potassium dichromate. Higher concentrations of petroleum hydrocarbons correlate with elevated CODcr values, though no fixed correlation coefficient exists.

Interrelationships Among Water Quality Parameters in Environmental Monitoring

Relationship Between TOC, CODCr, and CODMn
 

Total Organic Carbon (TOC) is a comprehensive indicator representing the total organic matter content in water expressed as carbon content. TOC employs combustion methods to fully oxidize organic matter, directly indicating the degree of organic pollution in water bodies. TOC, CODCr, and CODMn are all indicators measuring organic pollution levels in water. Test results from domestic sewage and industrial wastewater across various sectors show significant correlations between TOC and both CODCr and CODMn. Theoretically, CODcr expresses oxygen consumption in terms of oxygen (O₂) consumed, while TOC expresses it in terms of carbon (C). The ratio between them is O₂/C = 32/12 = 2.7. For specific water bodies, this conversion factor is sufficient. However, due to variations in water composition and organic content across different water bodies—and even within the same body of water due to seasonal changes, inflow conditions, production processes, and raw material variations—the conversion relationship between these parameters must be experimentally determined.

Probest with the PUVCOD900-TOC, PCM200-CODCr, PCM200-CODMn, PUVCOD-900-COD water quality monitoring Analysis. 

Interrelationships Among Water Testing Parameters in Environmental Monitoring

Total Dissolved Solids and Total Hardness

 

Since water contains eight primary ions, including Ca²⁺ and Mg²⁺, the total hardness of a water sample is defined as the sum of carbonate hardness and non-carbonate hardness. Non-carbonate hardness must be determined. When total hardness is measured using the CO DMn (acidic method), CO Dcr > BOD₅.

Interrelationships Among Water Testing Parameters in Environmental Monitoring

Total Dissolved Solids  （TDS) and Conductivity

 

Conductivity is the reciprocal of electrical resistance in aqueous solutions. The greater the concentration of soluble ions in a water sample, the lower its electrical resistance and the higher its conductivity. Therefore, a certain correlation exists between the conductivity and total dissolved solids (TDS) of a water sample. In natural water, the ratio of TDS to conductivity is approximately 0.55–0.70, though this represents only a rough estimate. If the water sample contains significant amounts of free acids or caustic alkalis, the ratio will be less than 0.55. Conversely, if the sample contains large quantities of salts, the ratio may exceed 0.70.

Water analysis monitoring instruments, also known as water quality testing equipment or meters, are used to assess water quality by measuring various parameters such as pH, dissolved oxygen, conductivity, turbidity, COD, and concentrations of different chemicals and contaminants

These sophisticated instruments are designed to measure physical, chemical, and biological parameters of water.

 Water quality analyzers are sophisticated instruments designed to measure various parameters in water, providing insights into its purity and safety. 

 

With the same function, Single or Dual-channel transmitter, measured parameters include PH, DO, ORP, conductivity, turbidity, SS, chlorophyll, blue-green algae and other parameters. And realize the plug and play of the

sensor, the configuration is flexible and convenient.

Both with the same Features

Achieve plug and play of sensors, quick and convenient electrode installation and replacement.

Simple to use, reliable results, interface operation instructions can reduce operation errors.

LCD screen visual operation, with Chinese and English bilingual navigation menu, rich and comprehensive interface content.

With 4 ~ 20mA, MODBUS RS485 multiple data output methods.

Automatically prompt error and alarm information, and realize the upload of alarm signal.

The transmitter supports wall-mounted installation/panel installation/ pinch tube installation.

Existing time display, data storage and historical data viewing functions.

Optional data wireless transmission module.

Diffence:
DXC20 is neutral type for OEM, ODM. 
UNI20 is with PROBEST logo, for our distributors. 

Since pH is very much related to the place of use, pH electrodes are marketed as wearing parts without warranty.
 

At the same time, the service life of in-line pH electrodes is largely dependent on the process conditions. pH electrodes have a service life ranging from a few days to more than a year without degradation of performance.

However, exposure to highly alkaline process conditions and extreme temperatures can shorten the life of the electrode.

We are pleased that the pH we sell at PROBEST, customer feedback has been used for over 6 years and is still good, my feedback has been used for over 2 years and is still good.

Be sure to tell the APPLICATION of use and choose the right PH electrode.

pH electrodes work by measuring the potential difference in mV between a glass membrane or X-chip and a reference electrode in a solution.
 

The pH-sensitive portion of the electrode detects the activity of the hydrogen ions at its tip. The silver/silver chloride reference electrode is in contact with the solution through a septum or open junction, providing a stable reference potential. The pH value is then calculated from the potential difference using the calibration parameters of the pH sensor (stored on the sensor for digital ISM sensors and on the transmitter for analog pH sensors).

Trust PROBEST chanagable PPH-500B ph online Sensor (Changable type) is your best choice for some cases. 
And we also have other types for your choice, for the complex industry, also for the pure water test.