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LIGO PRO 2 User Guide

From SOJI ELECTRONICS
Revision as of 10:44, 24 June 2026 by Admin (talk | contribs) (Initial Release [release])

Safety Information

ℹ️ NOTICE — Installer Qualifications and Safety
  • LIGO SP Fuel Level Sensor measures the accurate fuel level in fuel tanks, therefore the device installation process also needs to be extremely accurate.
  • Installation technicians should be well-trained by specialists or experts in this field before installing the device.
  • Implement protection against electric shocks and electrical fires, labour safety and hygiene.
  • List of installing tools is provided in section APPENDIX A below.
  • List of accessories is provided in section APPENDIX B below.

Product Overview

LIGO Fuel level sensor is produced and developed by SOJI Electronics Join Stock Company. The device is designed to measure the level of liquid fuels and other non-conductive liquids in vehicle's tanks and stationary fuel storages, applicable in different fields. The measured values will be t transformed into output signal in the form of: Analog, Frequency, RS232, RS485… and transmitted to a connected external device

Under particular conditions, the device can reach a high accuracy up to 99.5%. At present, on the market there are several lines of sensor using different technologies to measure fuel level such as: magnetically operated switches (reed switches), ultrasound wave (ultrasonic sensor), capacitive sensing (capacitive sensor). Among these ones, capacitive sensing technology is considered to have highest accuracy and greatest lifespan.

Package Contents

STT Description Qty
1 Ligo PRO 2 Fuel Level Sensor. Standard lengths: 700, 1000, and 1500mm (for other customized lengths, please contact the manufacturer) 01
2 Oil filter 01
3 Gasoline resistant rubber gasket 01
4 Anti-vibration spring when moving 01
5 1A Fuse protection 01
6 Self-drilling screw M4.8x32mm 04
7 Rivet and screw M5x20mm 04
8 Sealing wire 02
9 7m signal wire 01
10 Quick installation manual 01

Specifications

Parameter AF RS232 RS485
Standard length (L), mm 700, 1000, 1500 ... up to 6000 mm
Measuring error, % ± 0.5 %
Output signal Analog (0-9V) RS232 RS485
Baud rate, bit/sec 2400, 4800, 9600, 19200, 38400, 57600, 115200
Power supply (DC input voltage, V) 6-40V
Supply protection (Over-voltage 100 VDC for 2 min. Reverse polarity) Yes
Maximum power consumption, mA 20
Waterproof standard (IP) IP69K
Operating temperature, °C -40 ... +85
Maximum allowed humidity level, % 100
Resolution, bit 12
Output range (min level) Analog (0...8V) 0 0
Output range (max level) Analog (1...9V) 4095 4095
Average sampling period, s 0 ... 255
Message interval, s Continuous 1 ... 255 1 ... 255
Absolute error in temperature measurement, °C ±1
Bluetooth specs Bluetooth 5.1, IEEE 802.15.4-2006, 2.4 GHz, -95 dBm sensitivity, +8 dBm TX Power
Average service life, years (expected) 10

Installation

Selecting the location to install sensor

  • Installation location should be as close as possible to the geometric center and placed at the deepest level of the tank.

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Figure 1. Selecting the location to install sensor
  • When being installed, the sensor should not be in contact with reinforcement ribs inside the tank

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Figure 2. Installation of two sensors in one tank allows for significant reduction

Drilling the hole on fuel tank

  • Drill out the central bore by bimetal core drill ø38 mm
  • Drill out four mounting holes according to the diagram:

The mounting hole diameter depends on the tank material:

  • ø 4 mm – for metal tank with wall thickness over 3 mm (cut M5 self screw M4.8)
  • ø 7 mm – for plastic and metal tank with wall thickness up to 3 mm (for rivets)

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Figure 7. Installing revit nut if tank's wall is thinner than 3mm

Measuaring the tank depth and cutting sensor'measuring probe

  • Cut the sensor's measuring probe so that its length is 25 mm less than the depth of the tank. Ensure that shearing line is perpendicular to the sensor longitudinal axis

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Figure 9. Origin length (L) and length after cutting (Lm)

Notes: Minimum allowable length of the measuring probe is 150 mm.

Installing screen filter

Screen filter is mounted on the measuring probe of sensor to protect measuring probe electrodes from mud and water. Using the filter extends significantly faultless lifetime of the sensor.

Screen filter mounting order: firstly put on fixator, then put on bottom stop and fix it with two side screws. Put the screen filter over bottom stop and fasten it with a fixator locks.

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Figure 10. Installing screen filter procedue

Installing and connecting

  • Applying oil-and-petrol resistant non-conductive sealant to ruber gasket

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Figure 11. Applying the sealant to gasket
  • Put the sensor into the tank and fix: when fixing with rivets, use a rivet driver when bolting, put on a seal (per bolt), a spacer and a spring washer when fixing to plastic tanks with wall thickness over 3 mm, use vendor furnished self-tapping screws and a seal (per self-tapping screw)
  • Connect the sensors to an external device using 7m cable

The wire cable color:

RS232/RS485:

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Figure 13. Wiring diagram of RS232 and RS485 output signals
Wire Color Description
Black
GND (Ground) (V-)
Yellow
RXD/B-
Blue
TXD/A+
Red
12-37 VDC or 7.5-75V for SP PRO series

AF:

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Figure 14. Wiring diagram of Analog and Frequency output signals.
Wire Color Description
Black
GND (Ground) (V-)
Yellow
Out (Analog/Frequency)
Red
15-37 VDC or 7.5-75V for SP PRO series


  • Connect the fuse holder to LIGO sensor power cable (brown wire) in close vicinity to the vehicle power supply circuit
  • Installing the fuse in the fuse holder

Sealing

  • Install the bolt through a hole in the seal.

Configuration

Connecting sensor to smartphone and setting

To configure the LIGO AIR fuel sensor, download the LIGO BLE Configurator app on Appstore (for IOS) or CH Play (for Android devices).

Hereinafter LIGO BLE Configurator is referred to as the "application" or "app".

Note: For full operation, you must grant all the permissions requested by the app

Grant all the permissions request by program as above

Connecting sensor

Run the application and select the sensor you want to connect to, as shown in the pictures below:

Set Empty and Set Full

Step 1: Set Full

  • Immerse the sensor in fuel until the fuel reaches the sensor flange
  • Wait for C_working value to stablize and then press Set Full button

Step 2: Set Empty

  • Remove the sensor from the fuel and wait for 1-2 minutes allow the fuel drain from the measuring probe and then press Set Empty button.

Figure 21. Set Empty

Calibration table

After installation, the sensor must be calibrated to ensure accurate volume measurement. Calibration table can be performed either on the platform (server) or locally on the sensor.

  • Calibration table on the Platform (Server): The sensor sends raw level values (ranging from 0 to 4095) to the server via the telematic device. The platform uses a calibration table to convert these values into volume (liters).
  • Calibration table on the Sensor: The sensor directly sends volume values (liters) based on the internal calibration table.

Note: For LIGO AIR sensors, the manufacturer recommends performing calibration table on the platform.

Operation

Troubleshooting

Maintenance

Certification / Compliance

Refer to LIGO PRO 2 Certification & Approvals for current certificate status.

Support / Contact

Channel Detail
Company SOJI ELECTRONICS.,JSC
Address C50-LK13, Lot No. 09, New Urban Area, Le Trong Tan street, Duong Noi Ward, Ha Dong District, Hanoi City, Vietnam
Tel/Fax +84 24 62 932 369
Email contact@sojielectronics.com
Website sojielectronics.com


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