Float operated instruments can be the most accurate way to monitor water level. The new UNIDATA Model 6541 Precision Water Level instrument can achieve operating accuracy and resolution of 0.2mm. What’s more, this accuracy is maintained for the service life of the instrument without calibration or maintenance, apart from battery changes.
The 6541 instrument has the range to monitor surface and underground waters, and the precision to monitor rainfall and evaporation. The very low mechanical friction and inertia of the instrument mean that it can produce data with high precision and accuracy.
The 6541 supersedes the earlier 6509 and 6531 models but incorporates all their best features. The 6509 and 6531 have been installed at over 1 000 sites.
The 6541 instrument is normally "connected" to the water surface by a float system. On installation, the instrument is set to display the water level. An optical encoder is mounted on the input shaft so, as the water level changes, the input shaft and encoder rotate. The rotation of the encoder is continuously monitored so the instrument tracks water level changes. These changes update the LCD display and, if fitted, the readings can be recorded by a Micrologger.
A replaceable battery pack powers the instrument for more than 6-months and its practical design and rugged construction ensures easy operation and a long service life.
Your choice of encoding wheel diameter, length of floatline and type of float will depend on the site conditions and measurement objectives. Contact your local Unidata representative to discuss these requirements.
If you choose to include the 6541L Micrologger Assembly to make a permanent record of water level changes, you can also connect a telemetry system enabling you to monitor data acquisition, re-program the unit, and check the health of the site, all from a remote location. This can be done over landline, cellular, and radio communication links, whichever alterative is available and most cost effective at the installation site. Using this feature decreases the need for time consuming site visits.
Note that when you use one of the telemetry options you may need to provide external power such as a solar panel, external battery and regulator.