The new DS-Log4.0
In 2018, our 20 year old data acquisition and logging system has been completely redesigned, making it ready for the Internet of Things (IoT) :
- Wireless, long distance and power efficient data transmission into the IoT-cloud, without the need for a local central unit
- Real-time data access with our cloud-based data visualization platform DS-Cloud, including the possibility to add customized data processing routines and alerts
- Battery powered, several years of autonomy
- Complete electronic redesign of the measurement circuitry with new, high precision components
- Addition of thermocouple, Pt100 and universal voltage and current inputs to make the logger even more versatile
The DS-Log4.0 has a total of 48 input channels that can be used concurrently. The channels are grouped according to 6 different parameters (8 channels each group):
- Voltage (universal)
- Current (universal)
- Temperature (thermocouple J/K/N type, RTD 2-/3-wire)
- Corrosion potential
- Corrosion current
- Impedance (magnitude, phase angle, @ 1 kHz)
Thanks to the universal inputs, many analog electrical sensors with a DC-voltage or -current output can be connected to the DS-Log4.0.
For powered sensors, the onboard 3.3 Vdc output can be used as a power supply (total max. 50 mA).
The device reads the sensors at a predefined interval and sends the data immediately to the data server over the LoRaWAN wireless network, making the data available anytime. For backup purposes, the data is also logged locally on an internal SD-card.
The operating temperature ranges from -20 to +50 °C and the enclosure is watertight. The lithium battery typically lasts for 2 to 5 years, depending on the acquisition interval.
Input channels
| Range | Resolution | Int. resistance | |
|---|---|---|---|
| Voltage (universal) |
0 … +45 Vdc 0 ... +6.5 Vdc (HiRes) |
1 mVdc 0.1 mVdc |
280 kΩ |
| Current (universal) | 0 … +100 mA | 0.01 mA | 1.7 Ω |
| Corrosion potential | -1000 … +1000 mVdc | 0.1 mVdc | 100 MΩ |
| Corrosion current |
-1000 … +1000 µA |
0.1 µA | ≈ 0 Ω |
| Temperature (TC, Pt100, Pt1000) |
RTD: -25 … +80 °C TC: -25 ... +250 °C |
0.01 K 0.01 K |
-- |
| Impedance (@ 1 kHz) | 1 Ω … 1 MΩ | -- |
Applications
The DS-Log4.0 is the perfect data acquisition system for remote sites without access to a power grid and/or 3G/4G communication networks.
- Structural health monitoring *
- Steel loss of corroding reinforcement (corrosion current)
- Corrosion potential of the reinforcement
- Concrete temperature
- Concrete moisture (impedance)
- Condensation of steel parts (Time of Wetness, TOW)
- Static deformation and displacement (extensometers)
- Concrete technology: hydration temperature monitoring, maturity method
- Environmental monitoring (temperature, humidity)
- Geotechnical monitoring (displacement, crack width, tilt, water level (piezo))
- ... and many more; contact us for your specific needs
*) Together with the special corrosion and humidity sensors from TFB Diagnostic Systems, the DS-Log4.0 system is the ideal solution for long term corrosion monitoring of concrete structures.
Being one of the preferred transmission protocols for IoT devices, LoRaWAN is a wireless low-power wide-area networking protocol (LPWAN) for low bandwidth, battery powered devices such as sensor systems. It operates worldwide in a sub-gigahertz, license free band (e.g. EU: 868 MHz, US: 915 MHz) which makes it particularly efficient to penetrate buildings and civil structures. Typically, the transmission distance ranges from 2 km (urban), 15 km (suburban) up to 40 km (rural, free line of sight). Compared to other common wireless protocols such as WLAN or Bluetooth, LoRa has a much longer range while consuming less power than a 3G/4G device.
LoRaWAN operating in a license free band, anybody can build its own private network. In many countries, there are also public LoRaWANs operated by telecom companies (e.g. Swisscom in Switzerland) or community-based networks.
For our customers, TFB Diagnostic Systems operates its own private LoRaWAN whose coverage can easily be extended with additional gateways.
IoT cloud integration of the DS-Log4.0
Swisscom LoRaWAN coverage
DS-Cloud
DS-Cloud is a full-fledged, cloud-based data visualization and storage system. Based on a time-series database, it allows for customized data visualization and post-processing in real-time. The data can be accessed anytime with a standard web browser (desktop and mobile). An alerting functionality makes it possible to send alerts when a predefined threshold value is reached.
Data can easily be exported into third-party software for further processing and analyzing (e.g. Excel with a PowerQuery call).
Try out our demo instance:
https://cloud.tfb-diagnostic.ch (user/password on demand)