CAPACITANCE TYPE LEVEL SWITCH
- The principle of detection involved is the Capacitance phenomenon, which is developed between the probe and the reference.
- The amount of capacitance developed in any vessel is determined by the size (surface area) of the probe, the distance from the probe to its ground reference, and the dielectric constant of the medium being measured.
- As the media rises and falls in the tank, the amount of capacitance developed between the probe and the ground reference also rises and falls.
- This change in capacitance is detected by employing Radio Frequency (RF) and converted to a digital waveform proportional to the change in level which in turn is used for level detection and monitoring.
- Single Point Capacitance type Level Switch – This is to be used where only a particular fixed level is to be monitored. Output is relay contact, which can be used to operate, pump, agitator etc.
- Multipoint Capacitance type Level Switch – This switch is suitable when you need to control the level at various points (max up to 4 nos.) and can be used for most liquids. The output for each alarm points can be independent or latched.
- Each instruments comes with a probe electronics unit and a control electronics unit.
- The probe electronics unit senses the capacitance changes and converts it into an equivalent signal, which is processed by the control electronics unit for operating alarm set point(s).
- When the control electronics unit is merged with the probe electronics unit and housed inside the same probe unit housing, we get integral version.
- In case of non-integral version the control electronics unit is housed in a separate unit known as Remote unit.
- Besides for hazardous area application CMRI/ERTL approved Flameproof enclosure is also available.