User Manual & Datasheet V 2.1
1 Introduction
SLA is a admittance level limit switch utilizing specially
designed immuno coat probe offers a reliable solution to
level detection problems so far difficult to solve with ca-
pacitance type system utilizing conventional 2 element
probes. It consists of an evaluation unit, an electronic
insert and a probe. The probe is mounted either from
top or side of the vessel. The probe comprises sense and
shield electrodes, electrically isolated from the metallic
tank by the means of a suitable insulator. The two elec-
trodes form an imperfect capacitor with the service ma-
terial acting as the dielectric. Admittance measurement
using immuno coat probe give satisfactory solutions in
tough environments such as where;
• Conductive or non-conductive material coats the
probe.
• There is bridging of material between probe and side
wall.
• Material particles with electrostatic charge and vary-
ing temperature float in the vicinity of the Probe.
Figure 1: SLA
2 Operating Principle
The Sensitive portion of the probe and the container
wall (or ground electrode) from a means to measure
the admittance of the system with and without the
intervening material. When all the parameters that
affect the admittance value are kept constant then its
value changes only due to the difference in material level.
This change after amplification is used to operate a
relay, the output contacts of which are used for signaling
or control.
3 Measuring System
The complete admittance system comprises of the fol-
lowing:
• Probe of special construction immuno coat system.
• Electronic Insert ICA-3000A in plastic housing, fully
potted with epoxy resin.
• Evaluation Unit type LEVTESTER - SLA...Series.
Figure 2: Description of Parts
4 Features
• Ingress Protection of IP67.
• Coating Immunity specially for sticky and viscous
media.
• Universal Supply: 90 - 265V AC and 18V DC.
• Available in Integral as well as remote models.
• Customized mountings and probe lengths.
• Calibration possible from remote location.
5 Applications
• Food Industries & FMCG
• Sugar Industry
• Packaging Industry
• Foundry & Castings
• Soya Industry
• Bulk Material Handling
• Flour and Rice Mills
6 System Description
PROBE: The probe offers special construction with
two concentrically positioned electrodes, that are isolated
from each other and ground (Refer to Figure 2). The
innermost electrode serves as the sense electrode whereas
the next one is shield and the outermost is ground. Due
to the typical geometric configuration of the electrodes
and the maintenance of equi-potential
Sapcon Instruments Pvt.Ltd.
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