Compact Admittance type Level Switch

Intelligent and Self Checking

SAPCON 'ADMiRE' is a high-end RISC core microcontroller based level sensing limit switch, based on admittance principle. With it's specially developed algorithm it tracks the material trend continuously. In associaion with its 3-element probe utilizing the driven shield principle, it compensates for material build-up and thus It is immune to material build-up to a much larger extent. Simple push button type - hassle-free - calibration renders the unit installation and comissioning much easier. Failsafe selection and Cover/Uncover delays are settable any time while the device is in use. Available output options are PNP-NO and SPDT change-over relay. Power options are 10 to 55 VDC for PNP/NO and 85 to 265 VAC 50/60Hz for SPDT changeover type. SPDT with AC operation is also available in Flameproof enclosure.

Salient Features

- Easy to calibrate, using a push-button.
- Active build-up compensation algorithm - immunity against material build-up.
- Temperature stable circuitry - drift free reliable switching operation.
- Compact size and short insertion length, ideal for use in constricted places
- Low maintenance with no moving parts.
- Modular construction, so low down time.
- Driven shield system. Can tolerate certain amount of coating.
- Easy installation with switches and one bi-color LED.
- Selectable fail-safe condition (maximum/minimum)
- Configurable probe covered and/or uncovered delay.
- Failsafe PNP-NO output for DC and Changeover SPDT relay output for AC operation
- Wide operational supply range : 10 to 55 VDC for PNP-NO and 85 to 265 VAC for SPDT relay

Application

Sapcon 'ADMiRE' is ideal for use in constricted places due to its compact size and short insertion length. It can be used for detecting level in vessels containing granular solids , powders ; liquids and slurries. It can be used in dusty plant environment.

System Description

The sense and ground element of the probe form the electrodes of a capacitor with the service material as the dielectric. When the probe is not covered, the dielectric is that of air, whereas when covered, it is that of the service material. A change in the physical level of the material causes a change in the dielectric media between the two electrodes, thus causing a change in the measured capacitance. Using its three electrode sensing element, ADMiRE calculates the admittance of the capacitor being formed by the material. ADMiRE tracks the maximum and minimum values of the admittance change and thus tracks the status of material. If ADMiRE is operated in OPTIMIZATION mode, then it will give material by observing "material falling - admittance lowering" and "material rising - admittance increasing" trend , which will be guided by the calibration time set-point material to admittance relation. This continuous compensation will give correct switching output even when build-up is way too thick. When operated as normal level limit switch, it will give switching output as per above and below calibration time material to admittance setting. The covered and/or uncovered delay, can be set as desired. Calibration can be done easily with the help of a push-button. OPTIMIZATION is activated by setting cover-delay switch and uncover-delay switch to ON position simulteneously. ADMiRE circuitry is self compensating for ambiant temperature drift and thus reliable switching is ensured over the operating temperature range.

Technical Data

Evaluation Unit