The OTT CBS Compact Bubble Sensor is a compact, accurate, efficient, robust, and easy-to-use SDI-12 bubbler sensor for water level monitoring, which meets and exceeds USGS guidelines for accuracy. The CBS is low maintenance, with no desiccant required. A 5 year life is expected based on 1 minute intervals—no pump maintenance or lubrication required.

The CBS is contained in a compact ABS plastic housing and all programming can be completed using DIP switches on the back of the unit; connect into existing platforms using 3/8” O.D. or 4mm O.D. measuring tube.

Perfect for remote applications that require low power, the CBS’s intelligent pumping strategy compares the previous measurement to the actual pressure at the current measurement, and optimizes the pumping time depending on the difference (i.e., small changes in level are measured with very short pump cycles), saving on critical battery power.

  • Exceeds USGS guidelines for accuracy (±0.02 ft.). Higher accuracy version also available.
  • Measuring range: 0-50 ft (0-15 m)
  • Power consumption: 25 mAh/day @ 15 min. measurement intervals
  • Integrated purge function

Technical Specifications

Measuring range 0-50 ft (0-15 m)
Standard accuracy ±0.02 ft
High accuracy version 0-15 ft: ±0.01 ft

15-50 ft: ±0.065% of reading or ±0.02 ft, whichever is less
Resolution 0.003 ft / 0.014 psi
Units ft, psi, m, bar
Measuring interval 1 min to 24 hr
Max rate of level change 3 ft/min
Output SDI-12, 4-20 mA
Power supply 10-30 V DC
Power consumption 25 mAh/day @ 15 min. measurement intervals

320 mAh/day @ 1 min. measurement intervals
Compatible tubing 1/8 in., 2 mm or 4 mm ID
Temperature range -4 °F to 140 °F (-20 °F to 60°C)
Dimensions 6.5 in. (L) x 8.1 in. (W) x 4.6 in. (H)
Weight 3.3 lbs.
Integrated purge function Yes
Overload protection Yes


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