Conductivity is the ability of a material to conduct electric current. The principle by which instruments measure conductivity is simple - two plates are placed in the sample, a potential is applied across the plates (normally a sine wave voltage), and the current is measured. Conductivity (G), the inverse of resistivity (R) is determined from the voltage and current values according to Ohm's law: G = I/R = I (amps) / E (volts).
Since the charge on ions in solution facilities the conductance of electrical current, the conductivity of a solution is proportional to its ion concentration. In some situations, however, conductivity may not correlate directly to concentration. The graphs below illustrate the relationship between conductivity and ion concentration for two common solutions. Notice that the graph is linear for sodium chloride solution, but not for highly concentrated sulphuric acid. Ionic interactions can alter the linear relationship between conductivity and concentration in some highly concentrated solutions.
For more information on Conductivity Measurement, please visit our technical area
Conductivity can be measured in the laboratory using a bench
Conductivity Meter, in outdoor and field applications a portable Conductivity Meter would be used and for plant and process applications an online pH controller would be used.
Our EcoScan compact palm-top Conductivity meters are economically priced, user-friendly and simple-to-use features such as : Microprocessor based, easy and quick push button calibration, auto ranging, automatic temperature compensation (ATC), easy to read custom LCD, hold function, auto power off and self diagnostic.
The CyberScan Conductivity Meters are an ideal choice for anyone requiring to take measurements in rugged outdoor field work or in situ Plant and Process applications - being waterproof and robustly built, the chance of accidental damage is virtually eliminated. Not only is this instrument waterproof but in the event of accidentally dropping it into liquid, it will float to facilitate easy retrieval.
Choose from our wide range of Bench Conductivity meters, from the low cost, high specification CyberScan CON510 through to our top of the range touch-screen CyberScan CON1500. Incorporating advanced programmable features to suit the demands of today's scientist these meters make laboratory Conductivity testing procedures routine with user-customisable options. The CyberScan CON1500 has expanded Memory and can store and recall up to 100 data sets.
Our Alpha CON2000 is our top of the range industrial Conductivity process control instrument. These controllers can be wall-mounted or panel-mounted, are equipped with advanced menu-driven incorporated with a myriad of user-customizable features. Features include built-in PI/proportional control, scaleable current output for fine control, 2 independent set-points, alarm with timer control and programmable wash cycle. Output is scaleable for fine control, there is also hysteresis protection and noise grounding functions, etc.
At R.M.S Ltd we can supply replacement Conductivity Cells for both Industrial and Laboratory applications that are compatible with all modern instruments. All of our electrochemical sensors can be supplied with or with out temperature compensation. All we need is the make and model of your Conductivity meter so that we can determine the correct connector etc - please email, phone or fax us with your requirements and one of our team will contact you.