The measure of a liquid’s acidity and alkalinity, pH is one of the most common parameter measured in a wide variety of industries ranging from water and wastewater treatment, chemical production, agriculture research and production, environmental monitoring, chemical and life sciences research, biochemical and pharmaceutical research, electronics production to food processing and other industrial applications.
Eutech offers a wide range of pH meters that measure pH values in various educational, laboratory and industrial applications. These include the pHTestr™10, 20 and 30 pocket testers, portable meters CyberScan Series pH 300, pH 310, pH 11 and pH 110, EcoScan pH 6 and the CyberScan bench meter series 510, 1100, 2100, 1500 and the colour touchscreen research-grade series 6000.
Oxidation-Reduction Potential (ORP) or Redox potential measurements are used to monitor chemical reactions, to quantify ion activity, or to determine the oxidizing or reducing properties of a solution. ORP is a measurement of the electrical potential of a redox reaction and serves as a yardstick to judge how much oxidation or reduction takes place under existing conditions.
ORP electrodes measure the voltage across a circuit formed by the measuring metal half cell and the reference half cell. When the ORP electrode is placed in the presence of oxidizing or reducing agents, electrons are constantly transferred back and forth on its measuring surface, generating a tiny voltage. The ORP measurement can be made using the millivolt mode of a pH meter.
Major areas of usage include the treatment of industrial wastes, study of biological systems, oxidation of cyanide, bleaching of pulp, manufacture of bleach and reduction of chromate wastes. The measurement of ORP is also useful in pool water treatment as an indication of sanitation in relation to free chlorine parameter.
Eutech offers a wide range of ORP meters that measure both pH and ORP values in various educational, laboratory and industrial applications. These include ORPTestr™10 pocket tester, portable
meters CyberScan Series pH 300, pH 310, pH 11 and pH 110, EcoScan pH 6 and the CyberScan
bench meter series 510, 1100, 2100, 1500 and the colour touchscreen research-grade series 6000.
Eutech offers a wide selection of Ion Selective Electrodes (ISE) and meters for the measurement of ammonia, bromide, cadmium, calcium, carbon dioxide, carbonate, chloride, copper, cyanide, fluoride, iodide, lead, nitrate, potassium, silver, sulfide and sodium.
The ISE functions in the same principle as the pH electrode. The pH electrode is the most commonly used ISE that measures the activity of hydrogen activity in a solution.ISE responds to ionic activity or
concentration in a liquid because of the characteristics of the electrode’s sensing membrane. Ideally, the ISE develops an electrical potential which is proportional to the activity or concentration of the ion for which the membrane is selective. For example, the fluoride electrode can be used to directly sense fluoride ion in drinking water.
Electrical Conductivity (EC) meters measure the capacity of ions in an aqueous solution to carry electrical current. As the ranges in aqueous solutions are usually small, the basic units of measurements are milliSiemens/cm (mS/cm) and microSiemens/cm (µS/cm).
Conductivity is used widely to determine the level of impurities in water supplies for domestic consumption as well as industrial use. Industries that employ this method include the chemical, semi-conductor, power generation, hospitals, textile, iron and steel, food and beverage, mining,
electroplating, pulp and paper, petroleum and marine industries.
Specific applications include chemical streams, demineraliser output, reverse osmosis, stream boilers, condensate return, waste streams, boiler blowdown, cooling towers, desalinisation, laboratory analysis, fruit peeling and salinity level detection in oceanography.
Some applications require the measurement of Total Dissolved Solids (TDS) in mg/L, parts per million (ppm) or parts per thousand (ppt). The TDS concentration can be obtained by multiplying the conductivity value with a factor which is empirically determined. The total TDS is a mass estimate and is dependent on the mix of chemical species as well as the concentration while Conductivity is only dependent on the concentration of chemical species.
The total TDS is a mass estimate and is dependent on the mix of chemical species as well as the concentration while conductivity is only dependent on the concentration of chemical species. Some applications require the measurement of Total Dissolved Solids (TDS) in mg/L, parts per million (ppm) or parts per thousand (ppt). The TDS concentration can be obtained by multiplying the conductivity
value with a factor which is empirically determined. Eutech offers meters that allow the direct reading
of TDS values. These include the TDSTestr™ series, EcoScan TDS 6, CyberScan Standard Portables
CON 11, CON 110 and Waterproof Portable CON 410. Bench meters for advanced level laboratory
research are the CyberScan CON 510, CON 1500 and colour touchscreen research-grade CON
Salinity measurements are common in industries like agriculture, aquaculture, hydroponics, food, pools and spas where it is necessary to monitor the salt level constantly. The values are usually read in parts per thousand (ppt) or % (1 ppt = 1 gram per litre).
The Eutech Salinity Pocket Testers SaltTestr™ series and EcoScan Salt 6 are specially developed to provide direct readings in these applications.
DO stands for Dissolved Oxygen, which is the measure of amount of gaseous oxygen dissolved in a solution. In theory, the amount of DO in a solution is dependent on 3 factors, namely temperature, salinity and atmospheric pressure. The measurement of DO requires a special DO electrode that is made up of an anode, a cathode, electrolyte solution and a gas permeable membrane.
Colorimetry is defined as the measurement of a parameter whose concentration is proportional (directly or inversely related) to color intensity after the addition of known volume of reagent(s). Different chemical substances absorb different and varying visual light frequencies. Since the absorbance of a substance is proportional to its concentration i.e., a more concentrated solution gives a higher absorbance reading, therefore the concentration of a known solute can be measured using a
Eutech’s latest range of portable waterproof colorimeters measure Chlorine (Free and Total), Cyanuric Acid, pH, Chlorine Dioxide, Bromine and Ozone. The applications include water analysis in swimming pools, spas, public utilities, industrial wastewater plants, municipal water, treated water, water conditioning systems and paper and pulp mills.
Turbidity refers to the concentration of undissolved, suspended particles present in a liquid measured in
Nephelometric Turbidity Units (NTU). It is important to note that turbidity is a measure of sample clarity and not colour. Water with cloudy or opaque appearance will have high turbidity, while water that is clear or translucent will have low turbidity. High turbidity value is caused by particles such as silt, clay, microorganisms, and organic matter. By definition, turbidity is not a direct measure of these particles
but rather a measure of how these particles scatter light.
Turbidity is a very complex analytical measurement which can be affected by many factors. Some are inherent in the instrument’s design such as angle of detection, light beam aperture, incident beam wavelength and colour sensitivity of the photocell. However, there are other factors such as stray light, air bubbles and care of vial, which can be prevented through proper care of equipment and accessories.
One cost-effective and convenient way to measure multiple parameters without the need to purchase many different meters is to make use of a multi-parameter meter. Most of these meters are able to measure 2 or more parameters. The models featured here measure pH, conductivity and dissolved oxygen.
pH measurement is usually done with the use of a combination electrode. The combination electrode is an electrode system formed by a glass sensing half-cell and an internal reference half-cell. As the reference junction acts as the medium of conductor between the reference electrolyte and the sample to be measured, it must allow free movement of electrons through the junction and into the sample.
A potential develops on the membrane surface when a pH electrode comes into contact with a sample and its value varies with the pH of the sample. This variation in potential is measured in mV by a meter and is converted to direct pH values.