Water Quality Analysis
This text is machine translated.
About water analyzers
Water analysis devices are used in many areas in professional and private everyday life. They are used to determine different parameters, such as the pH value or the electrical conductivity of the water. Learn more about the types and functions of your measuring instruments in our guide.
-
What was a water analyzer?
-
Types of water analyzers
-
Purchase criteria for water analyzers – what is it all about?
-
Practical tip: Calibrate the pH meter
-
FAQ – Frequently Asked Questions about Water Analyzers
What was a water analyzer?
Water analyzers are a component of the wide range of measurement technology. As the name suggests, the purpose of these meters is to analyze water. The analysis will depend on the type of water analyzer. Chemical, physical and microbiological parameters can be analyzed. Depending on the model, the device measures, for example, the pH value, the water hardness, the conductivity or the temperature of the water. While dedicated analyzers such as pH meters are used to measure only one parameter, combi meters are capable of analyzing water in several ways.
Water analyzers are available in a wide range of designs and price ranges. They are used in many professional areas, for example to determine the water quality in drinking water and swimming pools or to determine the water load in natural waters or industrial waste water. The analyzers can also be useful for private purposes. An example of this is the use of pH meters in aquariums.
Types of water analyzers
In our online shop we offer you a wide range of water analysis devices for almost any purpose. Whether you are looking for pH testers to measure the pH in your aquarium or garden pond, need measurement technology to determine the conductivity of water samples or need a combination device for school or research purposes – we can help you find the right solution. Our range of analytical instruments offers a range of functions, different technical equipment and different price ranges – suitable for every application. Below is an overview of the available types of water analyzers.
pH tester
PH meters, also known as pH meters, determine the pH value of a solution, thus providing information on how acidic or alkaline the water is. The measurement is done electrochemical. It is often based on the potential of a glass electrode ("pH electrode"). If it comes into contact with the solution to be tested, an electrical potential arises which is directly dependant on the concentration of the positively charged hydrogen ions in the liquid. The voltage resulting from the potential difference to the reference electrode (integrated in the device) indicates the pH value. PH meters are available in various versions and, depending on the model, are sometimes calibrated according to the factory standard (with or without certificate) or ISO standard. For private purposes, such as determining the pH in the aquarium, simple pH testers in the form of test strips are usually sufficient, while for professional applications, high-quality devices are available, which differ in the measuring range, measuring accuracy and handling, for example. Because pH measurements often have to be performed outdoors, such as in baths or lakes, many pH meters are designed as handheld mobile devices that are battery-powered and ready to use at any time.
Conductance measuring devices
The fact that water is a good electrical conductor is a widespread misconception. It is not the water itself that directs the current, but the particles dissolved in it. Put simply, the more substances are in the water, the higher the conductance. A conductivity meter therefore enables the quality or load of water to be determined indirectly by determining the conductivity. The measuring device measures the electrical resistance of the water and indicates the resulting conductance in microSiemens (µ S). The higher the electrical resistance, the lower the conductance. Depending on the version, the TDS value (total dissolved solids) is also measured, i.e. the absolute number of dissolved substances. In order to ensure accurate measurements and accurate conversion, conductance measuring instruments often determine the water temperature. Knowing the conductivity is important, for example, to assess the quality of drinking water.
DO meters
Oxygen meters determine the O2 saturation of the water. The measuring instruments are also known as oximeters (sometimes oximeters) and are used, for example, in freshwater and seawater aquariums and in fish farming, agriculture and horticulture. The measurement can be carried out using a galvanic sensor, for example. This is a type of fuel cell in which a chemical reaction occurs when oxygen comes into contact with the contained potassium hydroxide. The result is an electrical current. The current indicates the oxygen concentration in the water, expressed in mg/l and/or as a percentage of saturation.
Photometer
Photometers are measuring instruments for the determination of different photometric variables. In the area of water analysis, they can be used to determine the load of water with certain substances, such as iodine or nickel. The basic operation is quite simple: A light beam emitted by the device passes the water to be examined. Depending on the intensity at which the light hits the measuring device's photocell, a certain concentration of the substance to be measured is obtained in the water. Devices are available for specific measurement of certain substances and models for measuring the "water color". The latter provides information on the presence of impurities of an organic or inorganic nature. Photometers are used, for example, for the analysis of drinking water and wastewater samples as well as for chemical water analyzes in the laboratory.
Combination measuring devices
These water analyzers combine several measurement functions in one device. There are models that can be used simultaneously as pH meters, conductivity meters, water thermometers and for measuring other parameters such as salinity and TDS. Since various factors play a role in the assessment of water quality, which also partly influence each other, these combi-measuring devices are practical helpers in the private and professional field.
In addition, water analyzers can be distinguished according to their design, handling and application.
Hand-held measuring devices
These devices are ideal for mobile use. PH handheld meters and other handy water analyzers usually point out with an easy handling and can be easily stored and transported.
Floor measuring devices
There are special pH meters which are only suitable for use in soil or in plant soil. They usually have a more robust pH electrode.
Measuring sticks
Measuring sticks are ideal for "quick measurement in between", for example for determining the pH value. They are easy to use and cost-effective and are often used in aquariums, among other things. An advantage is the equipment with temperature compensation, in order to ensure exact measurements at different temperatures.
Digital measuring devices
Most modern water analyzers are digital measurement technology that provides reliable and accurate results on a clear display. The measuring electrode can be replaced in many cases, was a long-term cost saving feature.
Purchase criteria for water analyzers – what is it all about?
Which water analyzer is right for your purposes depends essentially on what you want to use it for, how accurate the measurements must be, and whether additional features such as memory functions and interfaces for other devices should be available. In the professional sector, for example to determine the load of drinking water, industrial water, waste water or natural water, an exact analysis of the water values is essential, corresponding high-quality measuring technology is required. Pay particular attention to the type of calibration, the measuring range, the measuring accuracy and the recommended operating conditions such as temperature ranges and any necessary IP standards.
In the private sector, it is generally not necessary to obtain a comprehensive overview of the substances dissolved in water. For aquarists, parameters such as pH, oxygen saturation and water temperature are relevant, for which there are inexpensive one-test strips and inexpensive hand-held measuring instruments.
In our online shop you can filter the available measuring devices for water analysis according to different criteria and thus quickly find the right device for your needs. Among other things, it is possible to sort by the type of measuring device (pH meter, photometer, etc.), calibration, exact measuring function and existing interfaces (e.g. USB for connection to laptop and PC).
Our practical tip: Calibrate pH meter
It is recommended to calibrate pH meters regularly to identify deviations in the measurement results from the specified standard and to adjust the instrument. The longer and the more often a pH meter is used, the more likely measurement errors become. One or two buffer solutions are required for calibration (depending on whether a 1- or 2-point calibration is to be performed). We recommend solutions with pH value 7 and pH value 4. The exact adjustment can vary depending on the device. Some models have a calibration button, while others require you to use a suitable tool to turn on a "calibration screw" until the correct result is displayed. As a general rule, refer to the Instructions for Use for your device for detailed calibration instructions.
Learn more about calibration of meters >>
FAQ – Frequently Asked Questions about Water Analyzers
How often do you need to calibrate a water analyzer?
Many water analyzers come calibrated to you in new condition, however it may be advisable to perform a calibration before first use. How often you should calibrate the meter depends largely on how often it is in use and how much load the water in which the measurement technique is used. Observe the manufacturer's specifications in the respective data sheet.
Test strip or meter – what was better for aquarium fish?
Aquarium owners need water analyzers to determine if the water parameters meet the needs of aquarium animals and plants. Increased algae growth can, for example, indicate that water quality is slightly in the argen. PH test strips allow a quick determination of the pH value, while combi measuring strips determine several important parameters, such as the nitrate, nitrite and chlorine content as well as the water hardness. Whether purchasing a pH meter or a combined analyzer for aquariums makes sense depends on how often and to what extent measurements are to be made. Although test strips are available at a reasonable price, they can only be used once, so purchasing a water analyzer can be more economical in the long run.