FT836X series two-wire ultrasonic level gauge

The FT836X series two-wire ultrasonic level gauge is suitable for most applications. The instrument consists of an electronic unit, an explosion-proof casing, and sensors. The instrument does not require contact with materials and can be used for continuous level measurement in most applications.

　　measuring principle

The working principle of an ultrasonic level gauge is that the circuit controls the sensor to convert the electrical pulse group signal into sound energy and emit it. After the ultrasonic wave encounters the surface of the measured medium, it is reflected back, and then the returned sound energy is received and converted into the electrical signal of the sensor for analysis. Ultrasonic pulse trains propagate at the speed of sound waves, and the time interval required from emission to reception of ultrasonic pulses is proportional to the distance from the sensor to the surface of the measured medium. The relationship between the distance value S, the sound velocity C, and the transmission time T can be expressed by the formula: S=C * T/2.

Due to the certain width of the emitted ultrasonic pulse group, the reflected waves in the area close to the sensor overlap with the emitted waves, making it difficult to recognize and measure their distance values. As a result, the instrument will not function properly. This area is called the measurement blind spot. The size of the blind spot is related to the sensor.

The sound energy emitted from the sensor surface radiates outward, and the amplitude of the energy decreases as the distance from the sensor surface increases. The maximum sound energy is perpendicular to the sensor surface and radiates along the transmission axis. When the sound energy drops to half (-3dB), the conical boundary line will concentrate around the transmission axis once, which is called the beam. The angle of illumination of a beam is called the beam angle.

　　characteristic

Due to the use of advanced microprocessor technology and echo processing technology, ultrasonic level gauges can be applied to various working conditions.

The "Multiple False Echo Memory" function enables the instrument to correctly identify echo signals and obtain accurate measurement results in the presence of multiple false echoes.

The transducer is equipped with a built-in temperature sensor, which can automatically compensate for the temperature of the measurement results.

Chinese and English optional menus, LCD display makes debugging convenient.

Multiple display modes such as distance, level, current, percentage, etc. are directly provided to users with the desired results.

Typical applications

Liquid

Slurry

Performance indicators

Measurement equipment level: CAT I level, transient rated voltage 1500V, cannot be used for levels other than CAT I level

Output: 4-20mA

Measurement method: can be set as level/distance measurement method by software

Power supply: 15-30VDC

Power:< 1W

Accuracy: 10mm or 0.5% FS (whichever is greater)

Resolution: 4mm

Temperature effect: 0.2%/10 ℃ (18 ℉)

Load resistance: Output circuit load resistance capacity of 450 Ω at 24VDC

Environmental temperature: T5:- 40～+70℃(-40～158℉); T6:- 40~+60 ℃ (-40~140 ℉) (The influence of medium temperature on ambient temperature cannot exceed the instrument's requirements for ambient temperature)

Response time:<2 seconds

Delay: Adjustable from 1 to 90 seconds (software adjustable)

Range: max. 5m, 10m, 20m (different sensors have different maximum measurement ranges)

Beam angle: minimum 12 °

Electrical interface: M20 × 1.5 (optional 3/4 "NPT)

Process connection: G 2A threaded installation or DN150 flange installation (other optional)

Shell material: die cast aluminum with epoxy coating

Shell protection: Compliant with IP67 protection level

　　Probe indicators

　　Installation requirements for FT836X

The installation, use, and maintenance of the product should comply with the relevant provisions of the product installation, commissioning, and use instructions, GB50257 "Code for Construction and Acceptance of Electrical Equipment in Explosive and Fire Hazardous Environments", GB3836.15 "Electrical Equipment for Explosive Gas Environments Part 15: Electrical Installation in Hazardous Areas (excluding Coal Mines)", and GB3836.13 "Electrical Equipment for Explosive Gas Environments Part 13: Maintenance of Electrical Equipment for Explosive Gas Environments".

When installing instruments, they should be kept as far away as possible from vibration sources, high temperature environments, corrosive air, and any places that may cause mechanical damage. If the requirements cannot be met, please replace the instrument with a new component. The ambient temperature should be between -40 and 70 ℃ (-40 and 158 ℉).

The instrument installation area requires lightning protection devices to prevent lightning strikes.

It is prohibited to use single component ambient temperature sulfurized sealant inside the instrument casing. This substance often contains acetic acid, which will corrode electronic components. Special two-component sealant (non corrosive) should be used.

The instrument casing is equipped with grounding terminals, and users should ensure reliable grounding during installation and use. When used for non-metallic cans, a standard ground should be provided on site and cannot be connected to the power ground.

The electrical interface should be equipped with cable sealing joints with a protection level of IP65 or above that meet the requirements of GB4208 standard, to ensure reliable sealing and prevent damage to the instrument electronic unit caused by water ingress or other corrosive gases.

Do not disassemble the sensor or loosen the sealing nut to avoid probe leakage.

The installation of sensors should avoid material flow or inlet/outlet ports. If there are no other installation locations, protective covers or partitions should be added.

The installation of threads or flanges should be firmly connected to the container, reliably sealed, and have good electrical contact. Except for the connection, other parts of the sensor should not come into contact with the container to ensure good insulation.

When installing sensors, the installation space should be considered, with a minimum distance of 500mm from the tank wall.

In situations where there is significant stirring, airflow, and material flow fluctuations inside the container to be tested, it is recommended to use isolation plates to avoid affecting the measurement.

The sensor reference plane should extend into the tank by no less than 100mm. If this cannot be met, please refer to the relevant dimensions in the installation diagram below.

Please refer to the following installation diagram for other installation precautions.

The instrument circuit installed according to intrinsic safety standards must be equipped with safety barriers certified by GB3836.1 and GB3836.4 explosion-proof standards.

The ripple of 24VDC power supply shall not exceed 100mV.

The instrument connection cable shall comply with the requirements of IEC60245/60227 standard. It is recommended to use armored shielded 3-core cables with an outer diameter of no more than 12mm. The cable conductor material is copper, and the cross-sectional area of the conductor is 0.13-2.1mm2 (AWG14-26). The insulation strength of the cable is 1500V. Long distance unshielded cables cannot be used in parallel with AC power cables.

When using and maintaining on site, the principle of "no opening with power on" must be followed, and it is recommended to shut off the power for 10 minutes before operation.

　　FT836X Typical Installation