How to properly install an ultrasonic level gauge?

I. Installation Location Selection

1. Avoid Interference Sources:

The sensor should be installed away from locations with significant liquid level fluctuations, such as directly below the inlet or outlet, to prevent interference from agitators, foam, gas emissions, etc., which could affect measurement accuracy.

For conical containers, the instrument should be installed at the top center to ensure measurement of the bottom.

For arched or circular tank tops, multiple reflections should be avoided; the installation location should be offset from the center of the container top.

2. Consider Media Characteristics: Different liquids have different sound wave propagation speeds and absorption characteristics. Appropriate installation locations must be selected based on parameters such as dielectric constant and density.

II. Installation Height and Angle

Matching Range and Dead Zone:

The distance from the sensor’s emitting surface to the MIN liquid level should be less than the instrument’s range.

The distance from the sensor’s emitting surface to the MAX liquid level should be greater than the instrument’s dead zone (typically 0.3-1.0m, depending on the model).

If the distance between the MAX liquid level and the probe is less than the blind zone, an extension tube (diameter > 120mm, length 0.35-0.50m) is required, or the tube should be extended directly to the bottom of the tank (diameter > 80mm).

Verticality Requirements:

The sensor’s emitting surface must be strictly perpendicular to the liquid surface (an angle of tilt > 3° will introduce significant measurement errors).

Use a spirit level to calibrate the flange mounting surface to ensure the probe axis is vertical.

If the tank wall is not smooth, the instrument must be at least 0.3m away from the tank wall; if the tank wall is smooth, the distance can be appropriately reduced.

III. Installation Distance Specifications

Distance from Container Wall:

The recommended distance between the probe and the container wall is greater than 10% of the measurement range, and not less than 0.4m.

Specific Calculation: For smooth sidewalls, distance ≥ range × tan10° (e.g., ≥0.9m for a 5m range); for rough sidewalls, distance ≥ range × tan20° (e.g., ≥1.8m for a 5m range).

Centering Treatment:

If the container opening is not perfectly circular (e.g., a manhole), it is strongly recommended to install a short centering tube to ensure the center of the probe’s emitting surface is directly aligned with the geometric center of the container, reducing false echoes.

IV. Special Environment Handling

Handling Liquid Surface Fluctuations:

For liquids with drastic surface fluctuations, an ultrasonic level gauge with automatic power monitoring, a larger range instrument, or a submerged well can be used to measure the liquid level within the well.

Alternatively, an extended conduit can be used, allowing the conduit to extend directly into the bottom of the liquid level. The conduit diameter must be larger than the probe’s radiating surface.

Environmental Protection:

For outdoor installations, a sunshade should be used to extend the instrument’s lifespan and prevent direct sunlight and rain.

In areas prone to thunderstorms, it is recommended to install dedicated lightning protection devices at the instrument’s inlet and outlet terminals.

In particularly hot/cold environments, high and low temperature protection devices should be installed around the level gauge.

In areas with strong vibrations, rubber vibration dampers should be installed to reduce the impact of vibration on measurement accuracy.

V. Wiring Specifications

Wiring Safety:

Power Cable: Connect to the nominal voltage (e.g., 24VDC), ensuring correct polarity.

Output Cable: Commonly used for 4-20mA analog output; ensure signal type is correctly identified and connected to the corresponding terminal.

Professional grounding is strongly recommended: Connect the “GND” terminal inside the wiring cavity to a stable and reliable field grounding stake using a ≥2.5mm² yellow-green copper core wire.

Cable Protection:

Cables should be laid along a fixed path to avoid compression or pulling.

When installed outdoors or in humid environments, tighten the cable sealing sleeve to prevent moisture intrusion.

Cables should be bent and run downwards to prevent water or moisture from entering the instrument.

VI. Commissioning and Calibration

Parameter Settings:

Set key parameters such as installation height (distance from probe to tank bottom), range, zero point, and alarm value.

Set the response speed as needed (fastest, faster, medium, and slow speeds).

Liquid Level Calibration:

After powering on, input the actual liquid level value into the system via the menu settings to complete automatic calibration.

Perform empty/full tank calibration, check the echo intensity, and ensure measurement accuracy.

Functional Testing:

Add liquid to the container at different levels and observe whether the changes displayed on the liquid level gauge match the actual liquid level.

Test whether the equipment’s alarm functions, data logging, and other functions are working properly.

VII. Maintenance and Care

Regular Inspection:

Check the sensor’s secure mounting to ensure it is not loose or detached.

Clean the sensor surface to prevent dust and dirt from affecting measurement accuracy.

Troubleshooting:

If the measurement value is abnormal, check for issues such as power supply/wiring, blind spots and obstructions, and probe contamination.

For regularly erroneous values ​​that are approximately twice the actual value, change the “Operating Environment” menu value to “Sealed”.

Important Note: Before installation, carefully read the product manual to understand the specific requirements of the model; if possible, it is recommended that a professional technician perform the installation and debugging to ensure excellent measurement results.