LIGO AIR

LIGO AIR is a wireless fuel level sensor designed by SOJI Electronics for measuring liquid fuel and other non-conductive liquids in vehicle tanks and stationary fuel storage. Equipped with Bluetooth Low Energy 5.4 technology, LIGO AIR enables seamless, real-time data transmission without the need for complex wiring, making installation fast and reducing the risk of signal wire tampering.

File:LIGO-AIR-product-overview.png

LIGO AIR series Fuel Level Sensor

About LIGO Air

LIGO AIR is engineered for the transport telematics market where reliability, long battery life, and stable long-range wireless communication are critical. Typical use cases include:

• Fleet & transport — trucks, excavators, cement mixer trucks, heavy construction machines
• Marine — vessels and offshore platforms
• Power generation — diesel generators, backup power systems
• Industrial storage — oil storage tanks, stationary fuel storage
• Off-highway machinery — environments with high temperature and vibration

The LIGO AIR family supports three industry-standard advertising protocols selectable from the mobile app: SOJI (default), Mielta, and Escort — allowing seamless integration with existing telematics platforms.

Product Variants

The LIGO AIR series offers three versions, each optimized for a different operational priority:

Variant	Description	Battery Life	Range
LIGO AIR LxS	Standard cost-effective version for essential monitoring needs	6–8 years	Standard
LIGO AIR LxT	Extended-battery version for long operational life in harsh environments	8–12 years	Standard
LIGO AIR PRO	Long-range version with high TX power for obstructed environments	6–8 years	2× Standard

Manufacturer Part Number	Length L (mm)
LIGO AIR – L7S, L7T, LIGO AIR PRO – L7S	700 ± 3
LIGO AIR – L10S, L10T, LIGO AIR PRO – L10S	1000 ± 3
LIGO AIR – L15S, L15T, LIGO AIR PRO – L15S	1500 ± 3

Customized lengths up to 6000 mm are available on request.

Product Specification

Features

Category	Specification
Functionality	Wireless fuel level sensor with BLE 5.4 advertising
Measuring accuracy	± 0.5 % (up to 99.5 %)
Standard length	700 / 1000 / 1500 mm (custom up to 6000 mm)
Dimensions (head)	87.1 × 84.6 × 31 mm
Probe diameter	Ø 20 / Ø 36 mm
Weight	See variant datasheet
Battery	Built-in Li-SOCl₂ 3.6 V × 2400/2600/3600 mAh (replaceable)
Current consumption	9 µA (LIGO AIR), 27 µA (LIGO AIR PRO) in working mode; 4 µA in storage mode
Battery life	8–10 years (standard); 8–12 years (LxT)
Memory	Built-in 32 Mb EEPROM — 90 days of data logs, max 500 setting logs
Accelerometer	Built-in (LIGO AIR PRO)
Anti-mud filter	Yes — oil filter and anti-vibration springs
Connectivity	Bluetooth Low Energy 5.4, IEEE 802.15.4-2006, 2.4 GHz
Sensitivity	-95 dBm
TX power max	6 dBm (LIGO AIR), 19.5 dBm (LIGO AIR PRO)
Antenna	Directional — 1.5× range vs. typical market sensors
Advertising interval	5–10 s (LIGO AIR), 10–15 s (LIGO AIR PRO)
Casing	Heavy-duty metal structure
Operating temperature	-40 °C to +85 °C
Storage condition	15 °C to 30 °C, RH < 60 %
Ingress protection	IP69K (dust-tight, high-pressure / high-temperature water jet resistant)
Protocol support	SOJI (default), Mielta, Escort
Average service life	10 years (expected)
Warranty	3 years from shipment (battery excluded)

Dimensions

File:LIGO-AIR-dimensions.png

LIGO AIR series overall dimensions (mm)

Value-adding Features

Directional Antenna

LIGO AIR's directional antenna technology achieves communication range 1.5 times greater than typical market-available wireless fuel sensors. The directional arrow on the sensor cover indicates the optimal orientation toward the receiver.

File:LIGO-AIR-orientation.png

Correct sensor orientation — directional arrow must point toward the receiving device

Storage Mode

To preserve battery during transport and warehouse storage, LIGO AIR enters a low-power storage mode with consumption as low as 4 µA, extending shelf life dramatically. The sensor automatically wakes up when installed and triggered via the mobile app.

Built-in Anti-Tampering Design

Wireless transmission eliminates signal wires that can be cut or tampered with. The protective cap mechanism additionally prevents unauthorized access to the sensor body.

Heavy-duty Metal Structure

The reinforced metal casing meets IP69K standards — protection against dust, moisture, vibration, and high-temperature high-pressure water jets — ensuring sensor durability equal to or greater than traditional wired sensors.

Mounting Recommendations

• Install the sensor in the direction of maximum signal transmission. The directional arrow on the sensor cover must point toward the receiving device.
• Ensure a minimum clearance of 150 mm between the top of the sensor and any overhead metal surface.
• Mount as close as possible to the tank's geometric center and at its deepest point.
• Avoid contact with reinforcement ribs and other equipment inside the tank.
• Minimum allowable length of the measuring probe after cutting is 150 mm.

File:LIGO-AIR-clearance.png

Minimum 150 mm clearance from overhead metal surface

For complete step-by-step installation instructions, refer to LIGO Air Manual.

Solutions for Long-Range or Metal-Obstructed Environments

When the distance between sensor and receiver is long, or there are many metal obstacles, customers can choose LIGO AIR PRO (higher TX power) or install the LIGO AIR Adapter at the receiver side to boost signal reception.

Device combination	Bluetooth signal range
LIGO AIR + Telematics (tracker) device	Standard distance
LIGO AIR + LIGO AIR Adapter	2 × Standard distance
LIGO AIR PRO + LIGO AIR Adapter	4 × Standard distance

LIGO BLE Configurator App

LIGO AIR is configured via the LIGO BLE Configurator mobile app, available on:

• iOS — App Store
• Android — Google Play (CH Play)

The application supports:

• Device discovery and pairing
• Real-time sensor data view (fuel level, temperature, battery voltage, RSSI, firmware version)
• Set Empty / Set Full calibration procedure
• Protocol selection (SOJI / Mielta / Escort)
• Measurement and advertising interval configuration
• Password change for unauthorized access prevention

File:LIGO-AIR-device-list.png

LIGO BLE Configurator — device list

Full configuration instructions are documented in LIGO Air Configuration.

Telematics Integration

LIGO AIR transmits data via BLE advertising packets containing fuel level, battery voltage, temperature, firmware version, and operation mode. The sensor is compatible with any BLE-capable telematics device (FM tracker) that supports beacon scanning.

Compatibility

LIGO AIR has been tested and verified with major telematics platforms supporting:

• SOJI Protocol (native — full feature set)
• Mielta Protocol (Mielta Group compatible trackers)
• Escort Protocol (Escort Group compatible trackers)

Detailed advertising message format, hardware ID mapping, payload decoding examples and example AVL packet parsing are documented in LIGO Air Configuration (section "Protocol Integration").

Calibration

After installation, the sensor must be calibrated to ensure accurate volume measurement. Calibration can be performed in two ways:

Method	Description	Recommended
Calibration table on the Platform (Server)	Sensor sends raw level values (0–4095). Platform converts to volume (liters) using calibration table	✓ Recommended
Calibration table on the Sensor	Sensor directly sends volume values (liters) based on internal calibration table

Procedure (Set Empty / Set Full) is described in LIGO Air Configuration.

Safety Information

• Empty and ventilate the fuel tank before installation. For gasoline tanks, all fuel vapors must be removed to prevent fire or explosion.
• Do not expose the sensor to mechanical impact or pressure beyond rated specifications.
• If the sensor body or cap is visibly damaged, do not install — contact the manufacturer for replacement.
• The battery is not user-serviceable except by trained technicians using manufacturer-supplied replacement cells.
• Operating, transport and storage conditions must comply with the specifications in the Manual for the warranty to apply.

Certification & Approvals

LIGO AIR conforms to international regulations for wireless devices and industrial equipment. See full list of regional approvals and standards on the dedicated page:

➤ LIGO Air Certification & Approvals

Memberships

LIGO AIR's compliance with industry organizations (Bluetooth SIG, WEEE, Battery WEEE, etc.) is documented here:

➤ LIGO Air Memberships

Nomenclature & Classification Codes

Customs codes (HS, HTS, CN, ECCN), product part numbers, and country of origin information are documented here:

➤ LIGO Air Nomenclature, classification codes

External Links

Product Page

• SOJI Electronics — Official Website
• LIGO AIR Product Page

Documents

Document	Version	Last Updated	Download
LIGO AIR Datasheet	1.1	14/10/2025	📄 PDF
LIGO AIR User Guide	1.2	04/11/2025	📄 PDF
LIGO AIR Protocol Integration	1.1	27/08/2025	📄 PDF

Software

• LIGO BLE Configurator — App Store (iOS)
• LIGO BLE Configurator — Google Play (Android)

Compatibility

• LIGO AIR Adapter — Wireless signal booster for receiver side
• LIGO Pro BLE — Wired fuel level sensor with Bluetooth 5.2

Frequently Asked Questions

• Frequently Asked Questions - FAQ

Additional Information

For Software Errata, Product Change Notifications, and End-of-Life policy, please contact SOJI Electronics support.

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Latest documentation version: Datasheet v1.1 (14/10/2025), User Guide v1.2 (04/11/2025), Protocol Integration v1.1 (27/08/2025).