Rotary Paddle Level Switch-SE Series
Principle
The SE series operating principle is simple. A unit is usually located through a bin wall at the top, middle or low level of a bin. During normal operation (no material present) a synchronous motor rotates the paddle at 1 RPM.
When this paddle rotation is impeded by material, surrounding the paddle, the motor will stall and cause the Micro-switch to change state. (indicating an alarm or control)
Features
- An airtight sealing device, the outdoor application is available.
- Unique sealing ring design can perform good dust protection to avoid the dust permeates into the housing body along with the shaft.
- The torque force is adjustable.
- The performance of the torsion is stable and reliable.
- If the rotary paddle bears an extra overload, the motor will be appeared slide to prevent the inside mechanism damaged.
- It is rationally designed, the inside mechanisms are easily torn down for checking, maintenance, and replacement. It does”t necessary to remove the complete set from the tank.
- Very suitable for small tank and material of the low density
Capacitance Level Switch-SA Series
Principle
The capacitance level sensor measuring principle is base on the ” capacitance effects” when this level sensor is set on a silo, it will be formed a condenser between the detector electrode and the silo wall.
The capacitance of this condenser varies proportionally to the change of material-specific inductivity ( DK value) of the material stored in the silo when the more material substances increased in the silo, the more capacitance value-added simultaneously, then it will let his interior circuit’s resonant signal to create a bigger amplitude, and such a signal amplitude become more or less than factory default threshold value, the relay device will be energized.
Features
- No moving parts inside the device, it will be not affected by friction, which is suitable for powder or liquid application.
- Various models are suitable for different application.
- Operating temperature -20 ~ 200°C, Max. 800°C.
- The sensitivity, which includes 10pf, 20pf, and 40pf, is adjustable.
- With timing delay design, timing adjustable range 0 ~ 6 seconds.
- Voltage: 110V/220VacC or 24Vdc
- Output: NPN transistor, 5A/250Vac and 5A/240Vac SPDT contact.
- Standard connecting screw 1″ NPT, special specification are acceptable.
- Enclosure protection IP65 or explosion-proof.
- SA-75U Zener barriers inside provide intrinsic safety (Ex ia IIC) to SA17( )D type level switch.
Vibrating Probe Level Switch-SC Series
Principle
The vibrating probe of level switch operated by using two piezoelectric elements built-in on vibration tube. The first piezoelectric element triggered by a pulse signal created from the circuit to transport vibration energy out and the other piezoelectric element receives the vibration and transmits it to output electric signal.
While the probe contacts material, the detection signal will be decayed and the vibration will hold and send out the relay on. Vibrating probe of the level switch provides reliable & maintenance-free for bulk solids. Just a simple mounting and calibration procedure that keep your facility in save and monitoring. This device can withstand fiercely lateral loads and static electricity. For friendly use, Fail-safe is equipped as a standard to prevent malfunction caused by power shortage.
Features
- Sturdy and durable design. No calibration needed.
- Special design to avoid the accumulation of material on the probe.
- High / Low fail-safe modes
- Field-operatable in sensitivity adjustment to fit versatile density
RF-Capacitance/ Admittance Level Switch-SB Series
Principle
In order to eliminate false alarm given due to medium with high viscosity sticking onto the probe, a special material acting as an insulation electrode has been added in between the active section and the grounding section.
As shown in the diagram, the sensing probe always experiences medium clogging on it and thereby produces a capacitance and resistance between the 3 parts. Since the electric field between the
active section and the guard section is round-shaped, there will be no current passing through the medium between the electrodes.
The Admittance level switch uses this principle, to add a guard section between the active section and the grounding section to block the admittance current to reach the vessel wall from the medium between the active section and the grounded electrode. Although there would be a small
amount of admittance current between the guard section and the active section, the circuit would not take this current value into account.
Due to the guard section, only the admittance current change between the active section and the tank wall will be detected by the circuit, thus only when the sensing probe is in contact with the medium will there be a precise signal.
Features
- Not affected by material coating on the sensing probe.
- Easy installation.
- Stable operation, not affected by temperature.
- Time delay function of 0~90secs.
- Housing protection: IP65.
- DPDT /5A output.
- Maximum temperature: 550°C.
- High / Low fail safe selectable features.
- Applicable in liquid, syrup, solid, grain and interface detection.
RF-Capacitance Level Transmitter-EB Series
Principle
Capacitance Level Indicator: Utilizes the capacitance formed between the sensing probe and the metallic vessel wall. A high-frequency sine-wave is applied between the probe and the vessel wall.
A change of the medium level will induce a change in the current of the applied sine wave.
From Z=1/2pfc, when the capacitance in the vessel increase, the impedance will decrease and current will increase. Vice-versa, when the capacitance in the vessel is small, the impedance will increase and current will decrease accordingly.
Features
- Suitable for high temperature, high pressure, and corrosive environment.
- Not affected by noisy, dusty, misty and changes in the temperature.
- No blind distance, ideal for different tanks.
- Economic for large tanks
- 4~20mA output is compatible with most control systems and meters20. Ultrasonic Level Transmitter-EA Series
Ultrasonic Level Transmitter
Principle
The ultrasonic level Indicator is a low-cost, noncontact and easy-to-install measurement device. It is able to meet the every-day needs of commercial production, as well as serving a more specialized role in the technologically-advanced aero-space industry, thus placing it firmly in the category of high-level measurement technology.
Unlike other level indicators with limited uses, the easy-to-install ultrasonic level indicator is a highly-accurate device with enough specialized uses to ensure that the needs of the customer are met.
Features
- The non-contact style will not be affected by material character (such as Pressure, Viscosity, Density).
- Measuring range is available with 2M, 5M, 7.5M, 10M,15M, 20M, 50M
- Measuring accuracy of +/-0.25% in liquid resolution is 2 mm.
- Output: 2-wire, 3-wire, and indicator (transducer and controller are separated).
- Beam small angle, short blanking distance, is suitable for small tanks.
- Analog output : 4 ~20mA or 20 ~4mA.
- Supply voltage: 110 / 220VAC or DC24V.
- Suitable for powder and liquid application.
- Fail-safe function, can accommodate the possibility of transducer or power failure.
- Operating temperature: -20°C ~ 60°C. Enclosure rating: IP-65.
- Communication port : RS232, RS485. Relay output : 1~5 x SPDT.
Electromechanical Level Measuring System -EE Serie
Principle
EE200 Series Electro-Mechanical Level Measuring System has consisted of plumb, cable wire, measuring pulley, position sensor, and control board. When measuring, the sensing weight will drop down and cable wire will rotate the measuring pulley.
The position sensor and control board will calculate the distance of travel of the sensing eight (medium level) based on how many rotations measuring pulley accomplishes.
Features
- Measuring results immune from the interference of environments such as sound waves, dust, capacitance, or temperature change.
- User-friendly with microprocessor-based design.
- High level and low-level alarm.
- LCD Dot matrix: 8 x 2.
- Analog output: 4-20mA dc.
- Pulse output: Transistor output(NPN/PNP), Relay output(3A/250Vac)
- Cable Break Alarm: System will detect cable broken during the measuring.
- Plumb Buried Alarm: System will detect plumb buried by the medium.
- 4 Forms of Start Mode: auto start, manual start, intelligent start, and external start.
- Intelligent Start: Measuring interval is inverse proportional to medium level.
- Auto Return Setup: Prevent sensing weight from sliding into the tank to damage the equipment when the tank is empty.
- Material Fill-Up Protection: Reduce the possibility of plumb being buried.
- Measuring the range of 30 m.
- RS485 communication protocol.
- Various selections of plumb
Info : marketing@wmablog.com