Capacitance Level Sensors have the ability to detect and measure both conductive and non-conductive mediums such as water and oil, or solids (molasses, pastes, powder and grains), as well as a variety of other materials. In addition, this method is also applicable for detecting level when there are interfaces between liquids (such as oil/water).
Selecting the appropriate model and installing it in the proper location are key factors in successfully applying Capacitive Level Sensors. That is why Sitron offers many level measurement and control solutions.
Sitron's Capacitive Level Sensors are broken into two types:
1. Continuous Level Measurement (Models SC404, SC120 + CN200)
2. Point Level Detection (Models SC400+LV400 and SC700)
Like all of Sitron's products, the Capacitive Level Sensors can be made in a wide variety of process connections. They feature easy installation, as well as maintenance free reliability within a compact design.
Three elements are needed to form a capacitor: Two plates and a dielectric. The capacitance electrode (the probe) is one plate, the vessel wall is the other plate, and the medium is the dielectric. If the vessel is non-metallic, a conductive ground reference must be inserted into the vessel or a metallic tubular sheath can be placed over the probe's capacitance electrode to form the second plate.
A Capacitive Level Sensor measures level by applying a radio frequency (RF) signal between the capacitance electrode (the probe) and the electrically conductive vessel wall. The RF output creates a small amount of electrical current that flows through the medium (the dielectric) from the probe to the vessel wall.
When the level increases or decreases the dielectric constant, or the capacitance reading, increases or decreases. In other words, the level change results in a variation of the capacitance value around the probe, depending upon the degree of immersion.
For point level detection, the probe's electronics detect the change in the RF signal and then alter the state of the level switch. For continuous level detection, the probe's electronics convert the RF signal into a 4-20mA-output signal that is proportional to the change of the level.
- Wide range of applications/industries
- I.e. water, oils, corrosives, solids, powders, grains, etc. Functions on conductive as well as non-conductive medias No moving parts
- Rugged construction
- Easy economical installation Accurate and reliable measurement
- Unaffected by coating media or aggressive products Can operate at high temperatures and pressure