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Monitoring Water Quality Runoff From a Coalmine

Water Quality Monitoring Solutions from dataTaker

CAS DataLoggers provided the intelligent datalogging solution for an open-cut coalmine managing a high salinity water runoff into local retaining dams. The water from these dams could only be released into the local river system when it was of sufficient quality to have no effect on the irrigation of the surrounding farming district. Therefore it was necessary to closely monitor the quality of water in the retaining dam across several key parameters including pH. Management began searching for a data logging solution with the versatility to connect to a wide range of sensors and capable of remote access for convenient data accessibility. The recorder also had to be able to interface with a solar panel.

The coalmine mounted a dataTaker DT80 Intelligent Universal Input Data Logger into a weatherproof enclosures and connected it to a variety of sensors measuring water quality, conductivity (salinity), turbidity, pH, and water levels for measuring and logging the water quality, as well as thermocouples for water and air temperature. For example, a turbidity meter was used to monitor the cleanliness of the water. producing a 4-20 mA current output proportional to the turbidity which was passed through a 100 ohm shunt resistor to generate a voltage which was then read and scaled by the DT80. A solar panel and conditioner powered the dataTaker and charged the backup battery, which was also monitored by the DT80.

The DT80 datalogger was a cost effective device expandable to 100 channels, 200 isolated or 300 single-ended analog inputs, and also featured digital channels, high-speed counter inputs, phase encoder inputs and programmable serial sensor channels for connection to most sensors and data measurement sources. Nearly any physical value including temperature, voltage, current, 4-20mA loops, resistance, strain gauges, frequency, and more could all be scaled and logged. The stand-alone data logger featured a built-in display, 18-bit resolution measurement, and dataTaker’s renowned durability and construction providing reliable low-power operation even under extreme conditions. The DT80’s extensive communications array included RS232 with modem support, USB, Ethernet and USB memory stick ports so users could connect to the datalogger locally, remotely or over the Internet. The web interface allowed users to configure the DT80, access logged data and view current measurements as mimics or in a list using a web browser.

The dataTaker data logger could store as many as 10 million data points in its user-defined memory, offering independent control of schedule size and mode so that users could log only as long as needed. The DT80 also archived data on alarm event for maintenance purposes, copying to USB memory and transferring via FTP if needed for easy data and program transfer. Modbus slave and master functionality allowed connection to Modbus sensors and devices and to SCADA systems for advanced control capabilities. The DT80’s built-in web and FTP server enabled remote access to logged data, configuration and diagnostics. In this way, the dataTaker system allowed personnel to manually connect at any time to observe the change in water quality during water management operations such as mixing water from different sources. This wireless connection also enabled users to remotely adjust calibration parameters in the data logger in the event of a sensor replacement or program modification required by authorities.

Using radio telemetry via a freewave radio modem, personnel established a connection to a central PC in the mine’s office for periodic connection to the dataTaker for monitoring purposes. At these same intervals, the data was saved to a database, allowing for data backup and greater storage capacity than in the logger itself.

Additionally, the dataTaker DT80 included FREE dEX software with an intuitive graphical interface enabling operators to configure the datalogger, use mimics to view real-time data, create trend charts and tables, and retrieve historical data for analysis. This built-in software ran directly from a web browser and could be accessed locally or remotely, anywhere that a TCP/IP connection was available including globally over the Internet. Operators could use any of the logger’s built-in communications ports to view dEX including Ethernet, USB and RS-232.

The coalmine’s water monitoring operation benefitted significantly following installation of the dataTaker DT80 intelligent data logger, primarily by enabling measurement of all the different types of water quality parameters–all this data was made available through a single device. Personnel were also able to keep a constant watch on the data using the data logger’s remote access capabilities and rely on the logger to send the data to their company database for storage. The dataTaker’s included dEX software made configuration simple and was easily navigable for both novice and experienced users.