ECO BB9 Backscattering Sensor

The ECO BB9 is a sensor system for measuring optical backscattering at nine wavelengths.

WET Labs’ popular Environmental Characterization Optics ( ECO ) series tools determine bio-optical and physical parameters withi n natural waters. These instruments are designed as a modular suite of sens ors with special features for specific application support. The ECO series incorporates a common set of options with a single basic design to make the sensors idea for a wide variety of deployments.

The ECO BB9 is a flexible sensor system for measuring optical backscattering at nine wavelengths. The BB9 was developed to compliment the WET Labs family of spectral attenuation and absorption meters: the ac-9 and the new ac-s. Based on the successful line of ECO BB sensors, the BB9 uses a centroid angle of 117 degrees, which minimizes the error in extrapolating to the total backscattering coefficient

As part of an IOP package, the combination of a BB9, an ac-s and an ac-9 equipped with a 0.2 μm filter can define a, b and c: the inherent optical properties of the water column. The BB9 is designed as a flexible system. The BB9 c an be customized with any of the ECO line of optical configurations. For example, sc attering can be measured at seven wavelengths as well as CDOM and chlorophyll fluores cence. See the Triplet specifications sheet for details on the available o ptions. Further customization of the instrument is possible with pr essure and temperature sensors to provide a stand-alone profiling tool.



14.6 cm
Length30.5 cm
Weight in air3.1 kg
Weight in water1.8 kg


Wavelengths (nm)
and sensitivity
Sensitivity, 4882.14 x 10-5
Range~ 0.0024 - 5 m-1
Linearity99% R2


Digital output resolution12 bit
RS-232 output19200 baud
Input7-15 VDC
Current, typical300 mA @ 12 volts
Sample rate1 Hz


Temperature range0-30 deg C
Depth rating600 m (standard)


Specifications are subject to change without notice.


Customer Alert

ECO Pressure and Temperature Options Discontinued

Monday, August 10, 2015
August 2015 ECO TP Customer Alert.pdf
Customer Alert

WET Labs ECO Centroid Angles for Back Scatter Measurements

Tuesday, June 7, 2016
Product Brochure

BB9 Specification Sheet

Tuesday, February 12, 2013
Product Manual

bb-9 user manual

Thursday, April 27, 2017
Product Manual

BB9 User's Guide

Tuesday, February 12, 2013
Technical Note

ECO Calibration Log Template

Wednesday, February 22, 2017
Technical Note

Cable and Bulkhead Connector Maintenance

Thursday, March 9, 2017

What is the back scattering angle of my ECO instrument?

The WET Labs’ ECO sensors have multiple back scattering angles depending upon type of sensor. This document will describe these angles based upon the type of ECO sensor selected by the customer. [PDF]

What type of batteries are in ECO's?

  • We recommend the use of Lithium batteries in all of our ECO battery units.
  • There is a very significant battery life increase in comparison with Alkaline cells.
  • We use Ultralife Lithium +9V batteries.
  • Ultralife has 3 different part numbers (used with different sales packaging) for the long-life batteries we use in our ECO's:
    • U9VL
    • U9VLX
    • U9VLBP
  • Ultralife batteries have Aluminum/Mylar housing provding:
    • Protection against humidity and heat from entering the battery. Humidity and heat reduce efficiency and shelf-life.
    • Batteries that are much more leak-resistant.
  • Ultralife batteries have a 7-10 year shelf-life.
  • The batteries are customer replaceable with easy access to the battery pack.
  • The battery pack has 6 batteries: 2 layers of 3 +9V Lithium cells.

What is the memory capability?

  • Not included on the "RT" units!!
  • The memory is stored in "Flash" memory, an integrated circuit chip on the electronic board set.
  • There is no removable card, no upgrade in memory capacity.
  • The total sample records available for a single channel ECO = 108,000.
  • Typically, the ECO output is set to 1 sample/sec.