Substances with conductive aqueous solutions are referred to as electrolytes. These electrolytes are able to break down into ions when dissolved in water, thus creating free ions in the solution. Acids, bases, and salts are examples of electrolytes. Substances with non-conductive aqueous solutions are referred to as nonelectrolytes. These substances are often composed of covalent bonds, and examples include Carbon-containing compounds, fat, and sugar.
Solutions with high concentration of ions will exhibit high conductivity. On the other hand, solutions with low concentration of ions will result in small conductivity reading. A few factors that effect conductivity measurement are temperature, concentration of ions, and the nature of ions present in the solution. The probe also monitors the falling TDS levels in the boiler and shuts the blow down valve when the lower set point is reached.
In blow down applications it is best to use a self-cleaning probe. The sensing surface on normal probes scale-up over time and the probe must be removed for cleaning. A direct-contact probe must be chemically cleaned in weak hydrochloric acid and not by scraping or buffing the surface. Scratching the sensor increases the surface area in contact with the solution and alters the cell constant.
A self-cleaning probe overcomes much of this problem. It is important that the conductivity meter is properly earthed as required by the manufacturer. Because the probe emits and senses electric currents it will display readings from any electric current that presents to it.
Badly connected conductivity meter set-ups will give false results even though the meter reads true at the time of calibration. If this happens then check the electrical continuity of the sensing system and meter equipment. Web: trade-school. If you found this interesting you may like the ebook Process Control Essentials. Notice: JavaScript is required for this content. This site uses cookies to give you a better experience, analyze site traffic, and gain insight to products or offers that may interest you.
By continuing, you consent to the use of cookies. Learn how we use cookies, how they work, and how to set your browser preferences by reading our Cookies Policy. While all metals are generally good conductors of electricity, their conductivity differs depending on the atoms in the material and the structure. You have to pull a wire from metal and use a digital multimeter to quantify the resistance of the wire from one end to the other.
This is a non-destructive testing method that uses a portable metal conductivity meter to determine the electrical conductivity of different metals.
The technique is simple, more accurate, and abides by the national standards. A good metal conductivity meter will come with automatic temperature compensation and a simple calibration process to ensure accuracy. What is a Conductivity Meter? So, what is a conductivity meter, and how does it work? Contacting-type conductivity meter This type of meter has a probe with two metal electrode plates- cathode and anode set 1 cm apart that comes in contact with the solution.
Inductive conductivity meter Also known as toroidal or electrodeless conductivity meter, this inductive sensor consists of two wire-wound toroids encased in a corrosion-resistant plastic body. How to Measure Conductivity for Metal The electrical conductivity of a metal is simply a measure of how easily electrons flow through the metal.
There are two basic methods to measure the conductivity of metal; 1. Traditional electric bridge method You have to pull a wire from metal and use a digital multimeter to quantify the resistance of the wire from one end to the other.
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