Conductive Probes: What Are They

MMT produces high-quality conductive level probes

What Are Conductive Probes?

In level measurement, conductive probes are ideal tools for use with conductive liquids such as acids, detergents, and water-based solutions. However, they are not compatible with hydrocarbons, solvents, and oils due to their very low conductivity.

Typically, conductive level probes are used in safe inventory applications (to monitor minimum material levels) and help prevent tank overflow through two-point or multipoint control (pump control).

How the Conductive Measurement Principle Works:

An alternating voltage is applied between rod probes installed in an empty tank. When the conductive liquid enters the tank and establishes a connection between the reference base probe and, for example, the maximum-level probe, there is a measurable increase in current, causing the instrument to switch.

• For level control, the instrument switches again when the liquid clears the maximum-level probe.
• For two-point control, the instrument will not switch again until the liquid clears both the maximum and minimum-level probes.

Using alternating voltage prevents probe rod corrosion and avoids product degradation due to electrolytic effects.

The tank wall material does not affect measurement. If the tank is metallic, it can serve as a return electrode, saving the need for an additional probe.

Due to the very low electrical voltage involved, touching the probe rods while the system is operating is completely safe.

Advantages of Using Conductive Level Probes:

• Ability to monitor up to five level thresholds with a single probe.
• Two-point control, with additional maximum and minimum detection functionality.
• Option to choose between rod or rope versions for optimal application adaptation.
• No calibration required, thanks to standard settings for most common conductive liquids.
• No moving parts in the tank, ensuring durability, high operational reliability, and no wear, blockages, or clogging issues.
• Adjustable measurement ranges: 100 Ω, 1 kΩ, 10 kΩ, 100 kΩ.

For futher information about MMT products, visit the conductivity probes section.