Groundwater quality monitoring

The CTD-Diver is a fully standalone data logger with built-in memory, battery and sensors. Its ceramic casing and conductivity measuring range (0-80 mS) make it suitable for use at every measuring site.

The device is impervious to the most aggressive substances found in water environments. It is a compact data logger for the simultaneous measuring of groundwater level, temperature and conductivity. These parameters are measured at time intervals predetermined by the user. The measured values are stored in the data logger's memory and can be read out at any given time.

Programming the CTD-Diver takes only a few minutes in the field or at the office. The user can enter location, start time and sample rate and can also choose a fixed or an event-based sample rate. In the latter case, measured values are stored only if conductivity changes occur. A typical example is the increased pollution (conductivity) caused by an illegal discharge. The device can start measuring at a specified time.

The unit has three sensors: a pressure sensor to measure water level, a temperature sensor and a four-electrode sensor to measure conductivity. The internal memory can store up to 16,000 measurements for each parameter. All readings are date and time stamped.

With the use of a Direct Read Cable (DRC) and the DiverMate handheld data-transfer unit, the user can display the data without removing it from the monitoring well. Data can be retrieved from several units, which can later be transferred to a computer.

The data logger is supplied with the Logger Data Manager (LDM) software package. This software offers additional features such as a barometer wizard to compensate water level measurements for changes in air pressure. LDM also includes a calibration wizard for rapid conductivity sensor calibration. The data is stored on computer and can be exported in various formats to a spreadsheet program or database.