Liquid conductivity is the electrical resistance of uncharged fuel in the absence of ionic depletion or polarization. It is the electrical conductivity at the initial instant of current measurement after a DC voltage is impressed between electrodes. The test is designed to determine the rest electrical conductivity of liquids in the range 0.1 to 2,000 pico Siemens per meter (pS/m). The results find application in the assessment of electrostatic hazards since the generation and dissipation of electrostatic charge due to handling depends largely on the ionic species present which may be characterized by the rest (equilibrium) electrical conductivity.
Testing Principle and Methodology
The test applies to fuel liquid materials. The temperature of the material to be tested is determined first before testing since the electrical conductivity depends on the temperature of the liquid.
A DC voltage is applied to the surrounding outer cylindrical electrode and a pico-ammeter is used to measure current that passes through the sample to the inner electrode. Readings are taken 3s after application of test voltage for rest conductivity determination.
Before testing begins, the cell is washed with a low-conductivity liquid and then flushed several times with the test liquid. Liquid washes are discarded after every wash.
Applicable Standard
The test is conducted in accordance with the principles of ASTM D4308: Standard Test Method for Electrical Conductivity of Liquid Hydrocarbons.
Liquid Conductivity Test Cell manufactured by Anko
Data interpretation
Materials are classified according to their conductivity as low, medium or high. Materials such as Toluene and Xylene have conductivities less than 100pS/m and are considered to be low while materials such as Hydrogen Sulfide have medium conductivities between 100 and 10,000pS/m. Materials such as Isopropyl Alcohol and Acetone have conductivities greater than 10, 000pS/m and considered to be high conductive liquids. A material with a low conductivity would be considered insulating and therefore prevent the dissipation of charge. With such materials, it is possible for accumulation of charges at hazardous levels to occur which may in turn lead ignition of locally flammable atmospheres. Liquids with medium and high conductivities may lead to conduction or dissipation of charges and therefore prevent accumulation at hazardous levels. Knowing the conductivity class of your process liquid would ensure proper handling practices such as earthing of conductive and static dissipative containers of such liquids.
When to perform Liquid Conductivity Test
The test is recommended whenever there is possibility for a process liquid to become electrostatically charged. The ability of the liquid to accumulate and retain the charge is evaluated through the liquid conductivity test. The test is also recommended in various situations where the measurement of a liquid’s ability to conduct electricity is essential for assessing its quality, purity, or suitability for specific applications as well as its safe handling.
Why work with Prime Process Safety Center
- Prime Process Safety Center is a leader in process safety testing with very experienced laboratory personnel. At Prime Process Safety Center our goal is to provide accurate, reliable and defensible data that meets industry and regulatory standards. We understand the need for the quality of your data, and we work assiduously to achieve just that.
- We are knowledgeable and experienced in performing liquid conductivity tests, ensuring accurate and reliable results.
- We have state-of-the-art liquid conductivity testing equipment, providing precise and sensitive measurements.
- We follow strict testing protocols and quality control measures to ensure consistent and reliable test results.
- Our team can interpret and analyze the data obtained from the tests, providing valuable insights and recommendations for your specific application or research.
FAQs
What is Electrical Conductivity in Liquids?
Answer: Electrical conductivity in liquids refers to their ability to conduct electrical current. It is the result of ions or charged particles present in the liquid that allow the flow of electricity.
How is Liquid Conductivity Measured?
Answer: Liquid conductivity is measured using a conductivity meter or probe that applies a small electric current to the liquid and measures the resulting conductivity. The unit of measurement is typically picosiemens per meter (pS/m) or microsiemens per centimeter (µS/cm).
What Factors Affect Liquid Conductivity?
Answer: Various factors influence liquid conductivity, including the concentration of ions or dissolved substances, temperature, purity, and the presence of contaminants or impurities.
Why is Liquid Conductivity Testing Important?
Answer: Conductivity testing of liquids is crucial in assessing water quality, monitoring industrial processes, ensuring proper functioning of equipment, and controlling the composition of solutions in various industries such as manufacturing, environmental monitoring, and medical applications.
What Are the Applications of Liquid Conductivity Testing?
Answer: Liquid conductivity testing finds applications in water treatment, industrial processes, quality control in pharmaceuticals and food production, monitoring cooling systems, assessing wastewater, and ensuring proper functioning of various electronic and electrical systems.