Wireless Vibrating Wire Data Logger
The Worldsensing G7 wireless data logger collects readings from vibrating wire piezometers, extensometers, strain gauges and load cells and sends them to a gateway over LoRa. One-, two- and six-channel models support both periodic and event-triggered measurements. Sensors One, a Worldsensing partner, supplies the equipment, selects the network configuration and provides installation, setup and commissioning.
- Description
- Characteristics
- Solutions
-
Measurement Modes, Data Transmission and Mounting Options
Each Worldsensing G7 channel reads vibrating wire frequency and thermistor resistance. The logger checks both circuits for continuity, discards invalid readings if a connection is lost and flags the fault. Readings from the onboard barometer can be used for barometric correction. Internal temperature and humidity sensors help monitor enclosure conditions and detect sealing issues.
In periodic mode, the logger measures at a configured interval. In Triggered Measurements Mode (TMM), the onboard accelerometer initiates measurements when tilt angle, angular velocity or acceleration reaches a configured threshold. Users can set measurement timing, the number of readings and a delay. A separate local logging mode can record at intervals as short as two seconds. During this mode, regular transmission pauses and readings are stored on the device.
The logger is configured using the Worldsensing app over Bluetooth LE or USB-C. Readings travel to a gateway over LoRa / LoRaWAN. CMT Edge supports a single-gateway network, and CMT Cloud supports projects with multiple networks. Engineering formulas can convert raw readings into the units needed for analysis.
External-antenna models are available with one, two or six channels. The two- and six-channel RCR models use internal antennas and are designed for embedding in precast concrete segments, including tunnel linings.
-
Technical specifications
- Inputs per channel Vibrating wire sensor and thermistor, VW + TH
- Channel count 1, 2 or 6, depending on model
- Frequency measurement range 300–7,000 Hz
- Frequency resolution Less than 0.01 Hz
- Frequency measurement error 0.008–0.013%, depending on the excitation sweep
- Thermistor input range 0–4 MΩ, 1 Ω resolution
- Temperature measurement accuracy 0.04 °C at +25 °C, 0.4 °C over −40 to +80 °C. Values for a 3 kΩ thermistor
- Onboard sensors Barometer, three-axis MEMS accelerometer, temperature and humidity sensors
- Barometer range 260–1,260 hPa absolute pressure
- Operating modes Periodic mode and Triggered Measurements Mode (TMM)
- Reporting interval 30 s, 1 / 2 / 5 / 10 / 15 / 30 min, 1 / 2 / 4 / 6 / 12 / 24 h
- Local logging interval 2 / 5 / 10 / 15 / 30 s
- Radio WS LoRa / LoRaWAN, sub-GHz ISM band
- Radio range Up to 15 km line of sight, as stated by the manufacturer
- Configuration Bluetooth LE, internal USB-C, Worldsensing app, CMT Edge, CMT Cloud
- Power supply 3.6 V D-size LSH20 lithium cells. One cell for 1- and 2-channel models, up to two for 6-channel models
- Battery life Up to 15 years per the product page, depending on model, reporting interval and settings
- Operating temperature −40 to +80 °C
- Enclosure Aluminum alloy body, polycarbonate lid, IP68
- Surge protection IEC 61000-4-5, Class 2, ±1 kV test level, 2 Ω
- Weight excluding batteries 662 g for 1- and 2-channel models, 1,268 g for 6-channel models
-
Applications
- Pore water pressure and water level monitoring with vibrating wire piezometers, including instruments installed at multiple depths in one borehole;
- Ground displacement measurements between the anchors of multipoint borehole extensometers;
- Ground settlement monitoring with vibrating wire settlement cells;
- Total earth pressure measurements in embankments and tailings dams, including contact pressure at soil–structure interfaces;
- Monitoring crack opening on slopes and joint movement in buildings and infrastructure;
- Monitoring paste backfill pressure and barricade loads in underground workings;
- Measuring radial and tangential stresses in tunnel linings and shotcrete support;
- Measuring strain in steel arches and loads in supports and anchors with compatible vibrating wire instruments;
- Flow monitoring at V-notch weirs with a compatible vibrating wire sensor.
Leave a request — we will find
a solution for your facility
We will contact you, discuss the details and find a format
that is mutually beneficial.