The 6541 precision water level instrument is a high accuracy float and pulley based shaft encoder instrument for measuring the level of water in many different applications. Float-operated instruments can be the most accurate way to monitor water levels, and they are the most common method to measure river levels. The Unidata 6541 precision water level instrument can achieve operating accuracy and resolution of 0.2mm with high stability and minimum drift.
The 6547 radar water level sensor is 4-20mA two-wire instrument that provides continuous water level measurement of water in rivers, streams, open wastewater channels, stormwater overflow tanks and pump stations. The 6547 is a radar sensor which provides accurate long term measurements of water level up to 8m range from the sensor.
The radar SDI-12 version 6547S that provides accurate long term measurements of water level up to 15m range from the sensor is available as well.
This accuracy is maintained for the service life of the instrument without calibration or maintenance, apart from battery changes. The 6541 has the range to monitor surface and underground waters and the precision to monitor rainfall and evaporation.
The water level instrument is normally connected to the surface of the water by a float system. As the water level changes, the input shaft rotates. An optical encoder is mounted on the input shaft. On installation, the instrument is set to display the water level.
The encoder is continuously monitored as the instrument tracks water level changes. These changes update the LCD display and the readings can be recorded by an associated datalogger.
The very low mechanical friction and inertia of the instrument mean that it can produce data with high precision and accuracy. A replaceable battery pack powers the instrument for more than twelve months. Practical design and rugged construction ensure easy operation and long service life.
PHYSICAL SPECIFICATIONS
| MATERIAL | Powder coated aluminium mounting with Polycarbonate Enclosure IP66 |
| SIZE: | 180mm x 140mm x 275mm (LxWxH) |
| WEIGHT: | 2.7kg (including battery) |
| OPERATING TEMPERATURE: | -10°C to 60°C |
ELECTRICAL SPECIFICATIONS
| BATTERY: | 6 x 1.5V industrial grade D size Alkaline battery pack 6910A (non-rechargeable) |
| BATTERY LIFE: | up to 1 year (based on daily schedule) |
| EXTERNAL POWER: | External battery power 7-15VDC may be connected |
| RANGE: | Standard 0m-65.5m or -199.999m to 199.999m |
| ACCURACY: | 1mm, 0.2mm or 0.1inch depending on the chosen float pulley size |
| RESOLUTION: | 1mm, 0.2mm or 0.1inch depending on the chosen float pulley size |
| I/O: | 2 x HSIO bi-directional channels Up to eight instruments can be daisy chained Optional 4-20mA |
| SDI-12: | SDI-12V 1.3 recorder (1200 baud smart instrument channel) |
| LCD TYPE: | Reflective grey no backlight |
| DISPLAY FORMAT: | One line x 6 Characters, 7 segments |
| OPTIMUM VIEWING: | 6 o’clock |
| CABLE | 5m 8 core data cable |
INTEGRATED LOGGER SPECIFICATIONS - OPTIONAL
| STORAGE MEMORY | Low power CMOS RAM 512k standard |
| RAM BACK UP BATTERY: | Lithium Battery 3V, 950mAh |
| TIME CLOCK: | Crystal regulated, +/- 10 seconds/month |
| SCAN RATES | Programmable from 5 seconds to 5 minutes |
| LOG INTERVALS: | Programmable from 5 seconds to 24 hours |
| CPU: | 80C552 microcontroller, 14.7456 MHz |
