Level Sensors
Measuring principle
The functional principle of our capacitive level measurement is based on a changing condensator capacity. In this case, the probe rod and the tank wall form the two electrodes; the medium functions as dielectric medium. A level change causes a change in capacity. An empty tank has a low capacity; a filled tank has a high one.
Measuring principle
The functional principle of our capacitive level measurement is based on a changing condensator capacity. In this case, the probe rod and the tank wall form the two electrodes; the medium functions as dielectric medium. A level change causes a change in capacity. An empty tank has a low capacity; a filled tank has a high one.
The Sensor Amplifier
To guarantee the highest possible accuracy of the electronic unit for a possibly high number of media, CAPTRON uses a total of eight amplifier levels in one electronic unit. During a very simple calibration process, it autonomously chooses the ideal amplifier level.
The intuitive operating unit allows fast probe calibration with the help of three SENSORswitches only. A bright LED bar indicator was integrated in the operating element so that the level can even be read from a great distance. In addition, the bar indicator is not linear to allow a higher indication accuracy near the limit values. The user can also choose between different analogue and switching outputs. The switching points are represented optically. At the moment, three different versions are available that differ with respect to the output type. The electronics is provided with a robust M12 connector with 4 or 8 pins depending on the version. The housing is made of anodised aluminium or stainless steel (V4A) with slanted head in hygienic design.
Properties of the probe amplifier- The probe amplifier is firmly connected to the rod probe via a process connection. After installation, the probe amplifier can be moved to the desired position up to 350° by unscrewing the fixing screw.
Special features of the external amplifier- The external amplifier is connected to the rod probe via a shielded, temperature resistant teflon cable. Due to the spatial separation of the rod probe and the amplifier, these probes are suitable for temperatures up to 230°C. They can be mounted on a planar surface using the fastening flange.
The Probe Rod
The CAPTRON standard probe rod is made of virgin PTFE (teflon). It is available with diameters of 21 mm and 14 mm. The probe rod version can be selected: 1-rod version, 2-rod version and jacket tube version are available. One of the outstanding features of the probe rods is that they are not available in pre-fabricated standard lengths, but that CAPTRON produces each probe with a maximum length of 3000 mm to the nearest millimetre in line with the customer’s request. The compact design allows medium temperatures of max. 70 °C, the external version allows temperatures up to 230 °C.
Different tank types require different probe rod versions: In metal tanks that are electrically connected to the tank wall, 1-rod probes are used. In plastic tanks or in metal tanks with dielectric coating, either the 2-rod probe or the jacket tube probe is used. Due to its closed shielding, the jacket tube version has a higher measuring accuracy, but can only be used with liquid media.
Miniature Sensor- CAA-60 (Switching Output)
Compact probe with adjustable switching point. Available standard rod length 60 mm. Upon request, max. configurable rod length up to 600 mm. The switching output is available as both NC and NO.
- Suitable for liquid media
- Suitable for poorly conducting media such as PUR, epoxy, oil, etc.
- Exact switching point adjustable
- With switching output PNP-NC or PNP-NO
Miniature Sensor- CAA-60 (Switching Output)
Extremely robust analogue oil probe made of stainless steel V4A. The CAA-60 was especially designed for use in areas difficult to access. The complete design has been optimised to guarantee long service life. Attention was paid not only
to the heavy mechanical construction, but also to the simple, long-lasting electronics. The standard rod length is 60 mm.
- Suitable for liquid media
- Ex-works setting to determined medium, e.g. oil
- Analogue measuring range on whole rod length
- With analogue output 4-20 mA
