A cost-effective water level recorder. Comprises a water surface float-driven shaft encoder and internal data logger with rainfall input. Connects directly to compatible communications devices.

Hydrologger provides reliable, unattended, long-term monitoring of water level and rainfall. If you only want to record water level and rainfall, this is usually a less expensive option than buying a water level encoder and separate data logger.

Hydrologger can resolve a water level change as small as 0.2mm and is one of the most accurate ways to monitor water levels to millimetre accuracy. It maintains this accuracy for the service life of the instrument, without calibration or maintenance.

Like the 6541 water level encoder, it senses the position of the water surface using a float and counterwight system. As the water level changes, the float position changes. This change is coupled, via a beaded float wire, to a pulley attached to the shaft of the optical encoder. The shaft rotates as the water surface and float move up and down and the position of the water surface is encoded as a number. Up/down buttons, located behind the front lid, allow you to set this number so that the Hydrologger outputs actual water level.

The instrument displays water level on an LCD display on the front panel and provides outputs to conditionally control external devices.

Hydrologger integrates a low torque, high resolution, optical shaft encoder and Unidata Micrologger datalogger, bringing you a modern compact, simple to use, portable measurement and recording instrument. 

The Hydrologger can log data at intervals from 0.25 seconds to one week and can store approximately 100,000 water level and rainfall records.

 Hydrologger’s optical shaft encoder has a range of 0–65 m, providing 1 mm data resolution from its standard 500 mm beaded float line input pulley. An optional 100 mm circumference pulley provides a resolution of 0.2 mm.

Data from the Hydrologger may be downloaded via its RS232 port or, if required, can be remotely downloaded via a telemetry system.

The Hydrologger is compatible with Starlog software and is user programmable; recording interval, on-board data manipulation, reading external SDI sensors, or control of an output device.

Hydrologger data is available in ASCII format and is compatible with NIWA’s TIDEDA time series data manager and with other commonly available processing/archiving software.

NIWA Contacts