A water resource management company required a solution for monitoring water levels in boreholes up to 240 metres deep in remote Africa. The key challenges were the extreme depth, requiring a 250 metre sensor cable, and the need for a reliable remote data transmission system. The implemented solution paired a specialized submersible level sensor with a streamlined cellular IoT gateway to provide real-time data to a cloud-based platform.
- Customer Application: Piezometric level monitoring in deep groundwater wells (up to 240m) for environmental and water resource management.
- Key Challenge: Sourcing a submersible level sensor with a continuous, high-integrity 250 metre cable.
- Product Solution: An SLS-A series submersible level sensor connected to an IoT-Gateway-Lite for cellular data transmission.
- Benefit: Provided a robust, autonomous, and cost-effective system for accessing critical well data remotely via a web-based SCADA platform.
A company specializing in environmental solutions and water resource management in Africa was tasked with a critical project: monitoring the piezometric level of several deep wells across two remote sites. The data was essential for the sustainable management of groundwater resources in a region with a tropical climate. The project presented significant technical challenges, primarily due to the extreme depths of the boreholes, which reached down to 240 metres. This required a sensor solution with an exceptionally long, continuous cable length of up to 250 metres. Furthermore, the remote location of the wells necessitated a reliable, autonomous system for transmitting data to their central office for analysis by their engineering team.
The initial inquiry specified a preference for a system based on LoRa (Long Range) communication technology. However, the proposed solution pivoted to a more direct and readily available cellular-based IoT approach, which the customer was open to exploring. The solution consisted of two key components: a specialized submersible level sensor designed for deep immersion and a streamlined IoT gateway for direct-to-cloud data transmission.
The sensor selected for this demanding application was the SLS-A series submersible level transmitter. The sensor’s robust 316 Stainless Steel body and a drinking-water-approved EPDM seal provide further protection against the harsh downhole environment. The most critical feature for this project was the ability to supply the sensor with a custom, uninterrupted 250 metre cable length. This eliminated any need for cable joins, which are a common point of failure in deep well installations. The sensor was configured with a 4-20mA amplified output, a standard for industrial instrumentation that ensures signal integrity over very long cable runs without degradation.
For data acquisition and remote transmission, the IoT-Gateway-Lite was specified. This is a targeted version of the more comprehensive IoT-Gateway, optimized for applications where a single wired sensor needs to transmit data directly to the cloud. By forgoing the local wireless receiver capabilities of the standard model, the ‘Lite’ version offers a more cost-effective and simplified solution perfectly matched to the one-sensor-per-borehole architecture of this project. The gateway is designed to take the 4-20mA analog signal from the SLS-A sensor and use its integrated cellular modem to push the data to a remote, web-based SCADA platform. This provides the customer’s hydrogeologists and engineers with easy, real-time access to both live and historical data from any location using a PC or smartphone. Housed in an IP67-rated wall-mounted enclosure and powered by a 12-24Vdc supply, the gateway is ideally suited for field installation and can be connected to an autonomous solar and battery power system to ensure continuous operation in off-grid environments.
This combination of a highly durable, deep-range submersible sensor and a dedicated cellular gateway provided a complete and robust solution. It effectively addressed the customer’s core requirements for accurate piezometric monitoring at extreme depths, long-term reliability in a challenging environment, and autonomous remote data access for effective water resource management.
SLS-A Borehole Submersible Pressure Sensor
- Part No: SLS-A-DA-A250-BE-1001G-00
- Level Range: 0 to 100 mWG
- Range Type: Gauge, Vented Reference
- Output Signal: 4-20mA (2-wire)
- Accuracy Class: 0.25%
- Cable Type: PUR
- Cable Length: 250
- Cable Length Units: Metres (m)
- Housing Material: 316 Stainless Steel
- Seal Material: EPDM
- Diaphragm Material: 316 Stainless Steel
IoT-Gateway Lite Version Cellular Transmitter
- Part No: IoT-Gateway-Lite-00
- Analogue Inputs: 1 x mV/V 4-wire & 1 Analogue
- Digital Inputs: 8 x Volt-free Digital Inputs
- Outputs: None
- Display: None
- Options: None
- Cellular Connetion: 2G/3G/4G Transmit Bands MQTT Protocol
- Power Supply: 12-36Vdc