eLichens Avolta Wireless Gas Leak Detector

1. Introduction

Avolta is a wireless, battery-operated, Natural Gas leak detector. It embeds the Foxberry CH4NB sensor from eLichens, a cutting-edge NDIR (Non-dispersive Infrared), dual-channel sensor designed specifically to detect Methane, and only Methane. The sensor's ultra-high selectivity has been validated by the Chicago Gas Technology Institute (GTI) and prevents the generation of false alarms by volatile hydrocarbons. The Foxberry CH4NB sensor is based on eLichens' patented technology including a proprietary IR micro-source, patented optical design, and advanced signal processing algorithms. It provides the lowest power consumption on the market and is a key differentiator for battery-powered safety products. The Avolta leak detector is battery-powered and has an autonomy of more than 10 years, with the sensor constantly ON and a LoRaWAN heartbeat message sent every 8 hours.

2. Features

• Ultra-low power NDIR sensor
• Ultra-high CH4 selectivity: No false alarm
• Best sensitivity, detection as low as 5%LEL
• LoRaWAN + BLE connectivity
• Battery operated, 10-year lifetime
• Driftless, no recalibration required
• Fast response time
• Temperature & Humidity sensor
• Audible & visual alarms, test button
• UL1484 & EN50194 compliant
• Ingress protection IP54

Device Description: The device is a white, rectangular unit with a hose clip holder at the top. It features indicator LEDs labeled 'Power', 'Trouble', and 'Alarm', a prominent 'TEST' button, and a speaker grille. Dimensions are approximately 115mm height, 80mm width, and 35mm depth, with an Ø8mm hose clip.

3. Avolta at a glance

3.1. Global view

Device Components:

• LEDs: For visual status indication (Battery/Alarm/Defect).
• Sensing: Features an NDIR CH4-selective sensor and a T° & Humidity sensor.
• Alarm Thresholds: Adjustable alarm thresholds with 3 levels available.
• Power: Battery-powered with over 10-year autonomy; uses a replaceable battery.
• Test Button: Used for functionality testing and product configuration.
• Audible Alarm: 85dB with a pre-recorded alert message, which can be disabled.
• Connectivity: LoRaWAN + BLE connectivity, sending 1 heartbeat every 8 hours and immediate alarms (<30s). BLE is used for configuration.

3.2. Test button

Button Actions:

• Short press: Initiates a battery test. The 3 LEDs blink one by one, followed by a beep if the battery is OK.
• Long press (>3s): Initiates an alarm test. The device beeps, plays a pre-recorded message, and the red LED blinks during the message.
• Long long press (>10s): Initiates a LoRaWAN join request. A beep sounds after 3 seconds, followed by two beeps after 10 seconds. The device attempts to join the network, sending a LoRaWAN heartbeat message.

3.3. LEDs

LED Status Indicators:

• Green LED: Indicates battery and network status. Blinks every minute when battery lifetime is low. Blinks during LoRaWAN join request and blinks 3 times if the join request succeeded.
• Yellow LED: Indicates a product or network error. Blinks every minute when a sensor fault is detected. Blinks 3 times if the LoRaWAN join request failed.
• Red LED: Indicates a gas alarm. Blinks every minute when gas concentration is above the threshold.

5. Battery and start-up sequence

The Avolta is powered by a 3.6V primary lithium thionyl chloride battery pack with a capacity of 11.6Ah. The battery is non-rechargeable and is designed to last 10 years. Battery replacement must be performed by a trained operator only.

Upon delivery, the battery is inside the product but disconnected. To connect it, unscrew the transparent battery cover, plug in the battery connector, and then replace the cover, tightening the screws to ensure water tightness.

After the first battery installation, the product will initialize. The LEDs will blink one by one, and the green LED will blink every 3 seconds until the product connects to the network. If the connection is successful, the green LED will blink three times and stop. If it fails, the yellow LED will blink three times and stop.

The product requires approximately 6 more minutes to become fully functional. It is crucial to keep the product in a methane-free environment during these first 6 minutes while the sensor initializes.

6. Alarms

The product integrates several types of alarms: gas level, temperature level, and battery or electronics status.

6.1. Gas alarm

An alarm is triggered if the measured gas level exceeds one of the three programmed thresholds: small leak, alarming leak, or large leak. These levels can be reprogrammed via downlink commands.

6.2. Temperature alarm

An alarm is triggered if the measured temperature rises at a rate superior or equal to 3°C every 2 minutes (equivalent to 37°F every 2 minutes).

6.3. Battery/electronics alarm

The product performs constant self-testing. If a problem is detected, an alarm is raised immediately.

7. LoRaWAN join request

To connect the device to a LoRaWAN network, a join request must be initiated. Press the test button for more than 10 seconds. After 3 seconds, a first beep will sound, and after 10 seconds, two beeps will sound; you can then release the button.

During the join sequence, the green LED will blink every 3 seconds. If the join is successful, the green LED will blink twice quickly and stop. If the join sequence fails, the yellow LED will blink three times quickly and stop.

If the join request fails, try again; it can sometimes take 2 to 3 tries to succeed. Alternatively, leave the product powered ON, and it will automatically retry every 8 hours (heartbeat message interval) or if an alarm is raised.

Note: An automatic join request is performed at battery connection. If startup was successful, this manual join request is not essential, as the LED sequence described above occurs immediately after startup.

8. Payload format

Avolta sends two types of LoRaWAN payloads:

• Heartbeat payload: Sent every 8 hours to confirm the product is ON and fully functional.
• Alarm payload: Sent when one of the thresholds (CH4 level or temperature) is reached, or if an issue is detected (low battery or electronics failure). The product constantly self-checks, and the CH4 sensor is always ON. An alarm payload is sent within 30 seconds of detection.

The payloads format is described in the tables below (all words are MSB first).

Heartbeat Payload (every 8 hours on LoRaWAN port 1, without acknowledge)

Alarm Payload (every 2-5 minutes in case of an alarm on LoRaWAN port 2, with acknowledge. Retries up to 3 times if acknowledge fails)

9. Downlink commands

Downlink commands can be sent through the LoRaWAN network. The frame counter can be kept at zero.

Read commands

Write commands

Errors

10. Web data access (eLichens gateway or TTN)

If you are using a gateway provided by eLichens or if your area is covered by The Things Network (TTN), all collected data are directly accessible through a dedicated web interface. Access it here: https://lab.elichens.com/dashboard.

10.1. Account creation

To access the interface, connect to https://lab.elichens.com and create an account. Please adhere to the strong password policy:

• At least 8 characters
• At least 1 upper case [A-Z]
• At least 1 lower case [a-z]
• At least 1 digit [0-9]
• At least 1 special character [$@$!%*#?&,;:]

10.2. Associate a device

In the left menu, select "My stations". On your first visit, no station will be visible. Select "Associate a station" at the top right corner of the page.

Dashboard Interface Description: The eLichens dashboard interface displays a map of Paris with various sensor locations marked. Navigation options include 'My stations', 'Map', 'Pollution map', 'API doc', 'Profile', 'Satellite'. The 'My stations' view shows a list of stations and a button to '+ Associate a station'.

To proceed, enter the token provided by your eLichens contact or found inside the package. This is a unique code in the format AAA-BBB-CCC. Enter this code in the dedicated space and select "Associate the station".

A confirmation message will display, indicating that the station has been associated with your account. The "My account" section will show your username, email, and associated stations.

10.3. Devices' access

All connected devices are accessible through the left column of the interface. Buttons on the bottom right side allow you to change the history length. A click on "Advanced view" brings the user to an advanced dashboard where data can be exported in a .CSV file.

Advanced Dashboard Data: The eLichens Gas Leak Detection Dashboard displays real-time sensor data, including CH4 LEL (%), Temperature (°C), Pressure (hPa), and Humidity (%). It shows a time-series graph of these parameters and an Air Quality Index (AQI) map. Status indicators show 'Non explosive', 'Fully charged', 'Quite hot', 'Moderate', 'Quite dry', and 'Gas leak alarm'.

For more information, please contact:

eLichens SA
17 rue Félix Esclangon
38000 Grenoble
FRANCE
Email: info@elichens.com
Website: www.elichens.com