Cole-Parmer offers a wide range of conductivity meters and conductivity controllers for a variety of environments and applications. Our low cost pocket conductivity testers and portable conductivity meters are ideal for field based conductivity measurement. Many models have an onboard memory to store and recall conductivity readings taken. For laboratory based applications, select from benchtop conductivity meters including leading brands such as Oakton, YSI, and Thermo Orion. Features of this style of conductivity meter can include a computer interface either by RS-232 or USB. Speak to our Applications Specialists for free technical support on conductivity measurement to help solve your application needs.
When considering features for a conductivity meter it is important to first understand how conductivity measurements are made. Conductivity is the ability of a material to conduct electric current. Determination of conductivity is achieved by the instrument by placing two plates in the sample, applying a potential across the plates and measuring the current that passes through the solution. Conductivity, the opposite of resistivity, is determined from the voltage and current values according to Ohm’s Law.
Conductivity Meter & Measurement Selection Considerations
When selecting a conductivity meter important features that need to be considered are :
- Autoranging: Meter automatically selects the most accurate range for measurement. There is no need to manually change the range.
- TDS Conversion Factor: When a solution does not have a similar ionic water content to natural water or salt water, then a TDS conversion factor is needed to automatically adjust the TDS readings
- Temperature Compensation: A cell with built-in temperature sensor allows the meter to make adjustments to the conductivity or TDS reading based on changes in solution temperature
- Adjustable temperature coefficients: Alcohols and pure water are affected by changes in temperature differently than typical samples. An adjustable temperature coefficient allows the user to compensate for the properties of the measured solution
- Adjustable cell constant: Adjusts the measurement to reflect use of a cell with a constant other than K = 1.0. Wide range meters may except cells between K = 0.01 and 10