pH - Long live the electrode

pH Best Practices (Full version)

pH Best Practices (Short version)

Why you have to calibrate your pH electrode!

How often should I calibrate my pH electrode?
Probably one of the most common questions we receive, and there are no simple answers we can give. Directly, from the first time, when the electrodes are powered up, they begin consumed / drive. Consequently, you must calibrate the pH meter to the electrode's new features. Basically it depends on how accurate your measurements, pH, must be. Requires high (0.01pH) accuracy when the calibration shall be done every day. If the requirements are more normal (pH 0.1) or more of an indication of measurement, so you do not need to calibrate as often. After replacing the batteries or electrodes, the meter shall be calibrated.

How do I calibrate my pH electrode?
Most pH meter works the same way, with at least 2-point calibration. You should always check what is in its instruction manual. The calibration is always based on pH 7, which is neutral value. Then, you choose the second value pH4 or pH10, depending whether you should measure the acidity or alkalinity. When the meter accepted calibration passes it immediately to measurement.

pH electrode lifetime?
The lifetime of the electrode is dependent on several factors, see below:

An electrode used in low or high temperatures consumed faster than if the measurement is done in normal temperature 15 to 35 ° C. Therefore, to the extent possible to measure in these circumstances.

Acidic and basic
If the electrode is subjected to loads in the form of the pH swings, from acidic to Basque or vice versa, so consumed electrode's content (electrolyte) .Exempel: When measuring the pH value is low and at the next high (from below pH 5 to above pH 9) or vice versa. If this happens regularly, we recommend first of all using different gauges, one for the high pH and a low pH alt. pH electrode with påfyllnadsbar electrolyte.

It is particularly difficult to measure the pH of the protein-rich environments, such as food, beauty creams, meat etc. Proteins dirty very easily down (clogging) electrode and makes it slow.

How often do you measure
Life expectancy is affected by how often you measure. Especially when you are measuring in solutions that are troublesome.

Care and Maintenance
In addition to rinsing the electrode in water after use, is the best way to get the electrode thoroughly clean using a Hanna Instruments special cleaning solutions.

Always store the electrode in the storage solution (KCl). To a pH electrode should provide the best response time and accuracy, the electrode must be kept wet. The reason for this is that a constant jonkonce



The measured value of conductivity is indicative of how clean the water is. The method of measuring the level used extensively in clean-, rinse-, processwater, etc. ie in water affected by man or by other means.
We offer instruments that can cope with everything from deionized / distilled water to the worst-case scenario leachate, etc.
Be sure to find out the measuring range for best results.
Conversion Table
1μS / cm = 0.1ms / m
1mS / m = 10μS / cm
1mS / cm = 1 000μS / cm



ISO standard for turbidity is FNU (Formazine Nephelometric Unit) or NTU (Nephelometric Turbidity Unit).
Purification of drinking water
Turbidity is one of the most important parameters used to determine the quality of drinking water. Public water suppliers are required to treat their water to remove turbidity. The World Health Organization indicates 5 FTU as the highest value for turbidity. This value has been determined based on the appearance of the water. From a hygienic point of view, 1 FTU recommended value. Turbidity is an indicator and will not produce results for a given pollutant. However it gives information about the degree of the overall contamination.

Monitoring of natural water
In natural waters provide turbidity measurements a certain measure of aquatic organisms. It has been found that there is a strong correlation between turbidity level and the BOD value. Furthermore, prevent turbidity light, reducing the growth of marine plants, eggs and larvae, usually located in the lower levels of an aquatic ecosystem.

Sewage treatment plants and turbidity
Historically, turbidity been one of the most important parameters for monitoring of wastewater. Nowadays the measurement of turbidity at the end of the wastewater process, necessary to verify that the values ​​are within regulatory standards. In general, the turbidity value between 0 and 50 FTU, with an accuracy of ± 3 FTU, depending on the phase of the treating process the case. By monitoring the turbidity level, one can determine whether the various steps in the process, particularly in the filtration and purification steps are executed properly.



Oxygen is vital
The air contains approximately 20.9% oxygen. When air comes into contact with the water, dissolve a quantity of oxygen. The amount depends on several factors. Example: the time it takes for the system to reach equilibrium, the water temperature and salt content, if there are substances in the water that consume oxygen, etc. Since the oxygen content of water is important for biological and chemical processes, it is necessary to control this.

The electrode function
Our oxygen electrodes is based on a permeable membrane for direct measurement of the content. Oxygen diffuses through the membrane and electrochemically reduced at the cathode. The voltage between anode and cathode is predetermined and sized so that only oxygen is reduced. The higher oxygen partial pressure, the more oxygen diffuses into the membrane. This results in a change of current which is proportional to the oxygen in the sample.

Measurement results
The content of oxygen is usually expressed in mg / l of water, i.e. ppm or %. The electrode measures the partial pressure of oxygen. For a given pressure of oxygen in air, the concentration of the saturated, clean water to be fixed at any given temperature. Measurement results from a variety of measurements in pure water has been brought together through the years. The results are embedded in the meters that automatically compensate for temperature. This also applies to water salinity.



Fast measurements of the highest quality
We hit us for chest and says that the measurements photometers gives very similar to the response you get from water laboratories.
The measurement methods we offer are all very reliable and based on a well-proven metering mode. Nessler, DPD, Winkler, Phenol red etc are just a few examples, which provide high accuracy, which ensures highly secure results. It sounds sophisticated and complicated but it usually takes only a few minutes to obtain a measurement result. It requires no major prerequisites for implementing a sampling and the amount of water is only 10 ml / subject.

Many uses:
Industrial production
Critical environmental parameters such as pH, oxygen, nitrite, ammonia, chlorine and phosphorus, or pollution chromium, nickel, silver and zinc can be monitored.

Environmental Control
Critical environmental parameters that must be controlled in nature, eg, pH, dissolved oxygen, nitrite, ammonia, chlorine and phosphorus, or pollution chromium, nickel, silver and zinc

Careful control can prevent disease, increase production and also reduce
premiums on crop insurance.

Fish products
Being able to monitor and control the oxygen content, pH and nitrate content in water is vital to ensure profitable fisheries production.

Swimming pools and spas
To achieve the ideal water conditions in pool water requires testing every day for disinfection of waste products and maintain the pH level. Equally important is that the hardness and alkalinity monitored weekly to ensure water quality.

Plumbing and air conditioning
Being able to measure iron, chlorine, oxygen content and silicon is essential to avoid corrosion and contamination at both heating and cooling in different types of plants, cooling towers etc.

Nutrient analysis in greenhouses and hydroponic plants is necessary to maintain both quality and quantity, the harvests.


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