+91-731-4757575
LOH
Loss of Head Indicator
Sapcon LOH (loss of head indicator) is a perfect solution of measuring differential level in open channels and is widely used in water treatment plants and filter stations. The LOH series instruments are RISC Processor based capacitance type Continuous Level Indicators with built in three point switching. The system not only serves as a level indicator for conductive non conductive liquids, slurries and powdered or fine grained solids, but also offers switching functions for alarm annunciation and/or control application at the set point levels through the built in three point electronic level limit switch. The set points are independent of each other and are continuously configurable over the entire range.
Salient Features:
- Latest RISC core microcontroller technology.
- Measured level is displayed continuously from -50% to 150%.
- Multipurpose 5 digit seven segment LED display for best resolution and better viewing from distance.
- Two wire pulse coded digital communication from sensor to evaluation unit.
- Supports as much as 1 KM distance between sensor and evaluation unit with shielded two core cables.
- Galvanically isolated true two wire 4-20mA proportional to 0% and 100% level is available for remote indication purpose.
- Two wire implementation solves the malfunction problems that occurs with various PLC 4-20 input interfaces and thus better suits
- for higher end automation.
- 4-20mA loop can handle 700 Ohm loop resistance with internal isolated supply.
- Three independent potential free relays providing flexibility of selecting three independent switch points.
Principle of Operation:
The loop resistance can be 1K Ohm for External DC Supply of 24 Volts. In an application, the measuring electrode (sense probe) and the container wall (ground or reference probe) form a capacitor. The amount of capacitance of this capacitor is governed by the dielectric constant of the material between the two electrodes (sense probe & metallic container wall or reference probe or ground). The value of this capacitor is dependent on the level of material, since the dielectric of the material is effective only to the level to which the material is filled.
Evaluation Unit
| Housing | Cast Aluminum, Weather Proof, Stoving Enamel Painted. Suitable for back panel / wall mounting. |
| Cable Entries | 3 Nos. of / BSP/NPT |
| Operating Ambient Temperature | -20°C to +60°C |
| Power supply | Universal Mains 90 to 265 VAC, 50/60Hz and 24VDC (@ 3 Watt) |
| Sensor to Evaluation Unit Cable | 2-Core; resistance per core not to exceed 30 Ohms. Use of shielded twisted pair cables is recommended for long runs of cable. Cable lengths of 1000 meters are thus supported with grounded cable shields. |
| Utilizable span | 10 to 4500 PF |
| Zero% Range | 30pf to 250pf |
| 100% Range | 10pf to 4500pf (Difference from Zero %) |
| Outputs | Current 4 to 20mA. 3 Potential Free relays with One set of Potential Free Change Over Contact per Relay. |
| Contact Ratings | 6 Amp @ 230VAC 50/60 Hz for non-inductive loads. |
| Indication Continuous | -50% to 150% digitally on 1 ” Seven Segment Display |
| Switching | 5 mm Red LEDs’ for Alarm Indication. |
| Switching Hysterisis | 1% in Single Point Switching, 1 to 98% selectable in Pump Control. |
Loss of Head indicator Fail Safe Select Set Point Select Weight Electronic Insert Housing Plastic Power Supply Measuring Frequency Operating Ambient Temperature Sensitivity Output
| Field Selectable through interactive relay configuration menu. |
| 2.3 Kg Approx.N |
| - LDC117, LCDM 111 |
| potted with epoxy resin. |
| 16VDC @ 5mA derived from Sensor Communication Interface of Evaluation Unit. |
| 250Khz to 20Khz. Reverse Frequency Measurement. |
| 20 C to +60 C |
| 10 counts per pF |
| Digitally Encoded Current (5mA-8mA) Pulse. |
Probe
Probe Head : Cast Aluminum weather proof Mounting Flanged or screwed as per requirement standard Length 750 to 1500 mm Rigid, with grounding tube as reference and still-well. Insulation Full PTFE NB: |
