DTS-12 Digital Turbidity Sensor
The DTS-12 wiper system is the culmination of a comprehensive research and development program evaluating over 40 different cleaning technologies, lab and field tests, and years of field-based knowledge. The humble wiper's combination of effectiveness, reliability, and low power requirements made it the best choice over more exotic approaches. However, traditional wipers have short life spans and can become soiled, repeatedly dragging abrasive materials and organic matter across the lens optics. The DTS-12 wiper blade 'parks' in two grooves cut into the sensor face. These grooves extend the long term flexibility of the wiper, allow increased wiping pressure and clean the blade between wipes. Wiper changes are simple and inexpensive.
SDI-12 Digital Sensor
On-board support for statistical data processing, including filtering
algorithms, averaging (take as many as 100 readings in 5 seconds), median,
and B.E.S. increase your ability to obtain the most meaningful data from
any water system. The SDI-12 digital protocol provides easy connection to
any SDI-12 compatible datalogger, support for long cables, and assured
data integrity. Calibration coefficients are stored on-board at the
factory so sensor installation and swap-outs don't require entering
calibration data into your datalogger.
Shallow Water Capability
The DTS-12 was explicitly designed to avoid the viewing
problems of other turbidity sensors. Some have large viewing volumes for a
good water sampling average but are not capable of shallow-water
deployment while others have shallow water capability but have a very
small sampling volume. The approximately softball sized view of
the DTS-12 provides a good sampling volume and near-bottom
deployment.
Superior Accuracy
The DTS-12 features precision accuracy from 0 - 1600 NTU, eliminating the frustrating trade-off between low
end accuracy and wide dynamic range. The sensor also offers
excellent thermal and long term stability and nearly linear response over
three orders of magnitude.
Laser Based Optics
The DTS-12 uses optical backscatter technology
with a 780-nm laser emitter with automatic power control. It measures
suspended solids with an infrared measurement system incorporating optical
feedback and synchronous detection to reject ambient light. The DTS-12 features high accuracy, excellent thermal and long-term stability,
and nearly linear response over three orders of magnitude.
The Angled Head
The unusual geometry of the sensor head was designed after detailed
analysis demonstrated significant advantages for an angled sensor face.
Lab tests showed that an angled head did the best job of shedding the
bubbles that can form on the face of a sensor and give false turbidity
readings. The angled head also allowed us to combine 90° backscatter
sensing technology and our target sampling volume with a downward looking
'view', thereby significantly simplifying mounting and siting
requirements.
The optical system, lens face and wiper blades have been designed for extended field life, even in high abrasive-load waters. After accelerated wear testing simulating five years of operation in abrasive enriched waters, wiper function remained within factory specifications and sensor readings were offset by only 2.9%, requiring only a simple recalibration.
- On-board statistical functions
- Long cable runs without signal degradation
- All calibration coefficients are stored in the sensor so datalogger reprogramming is not required when sensors are changed
- Compatible with all dataloggers that support the SDI-12 standard
Constructed and Designed to Run 24/7 for Many Years
- All metal components are stainless steel or anodized aluminum
- "O" ring sealed
- Extended duty cycle motor for many years of trouble free wiper operation
- Heavy duty miniature stainless steel universal joint for maximum life span
- Thick walled sensor housing designed to minimize damage from accidental blows or clamping pressure
- Depth rated to 98 feet
- Plastic components from Delrin™ or Noryl™, selected for field proven durability, longevity, and thermal stability
Range: 0 to 1800 NTU
Resolution: 0.01 NTU
Supply Voltage Range: 9.6 to 16V
Accuracy - Turbidity:
Accuracy: ±2% 0 to 500, ±4% 501 to 1600
Zero Offset: ±0.2 NTU
Temp Coefficient (0-40°C): <-0.3%/°C
Accuracy - Temperature: ±0.20°C
Current Consumption (typical):
Standby: 350μA
Operating: 50mA
Motor Wiping: 100mA
Depth Rating: 98ft (30m)
Wipe Time: 5sec Nominal
Operating Temp: +32° to +104° F (0° to +40°C)
Output: SDI-12 version 1.1
Measurements Returned
(Raw data consists of 16-bit samples taken 20 times per second)
Instantaneous Turbidity
100 sample Mean and Variance
100 sample Median
100 sample BES
100 sample Min
100 sample Max
Dimensions:
length: 12in (30.48cm)
diameter: 2in (5.08cm)
shell thickness: 0.129in (0.38cm)