The Environmental Characterization Optics (ECO) series of sensors incorporates a common set of options with a single basic design to make them ideal for a wide variety of deployments.


  • Combines the unparalleled sensitivity of the ECO fluorometer with an optical scattering measurement at 700 nm for simultaneous determination of turbidity
  • Ranges for output are tailored to the environment
  • Allows for assessment of fluorescence and turbidity variability and interactions
  • Digital and analog output for easy integration into analog CTD packages or serial data streams
  • Provides excellent precision, reliability and overall performance at a fraction of the cost and size of similar sensors


Diameter 6.3 cm

12.7 cm (standard) / 17.78 cm (deep)

Weight in air

0.4 kg (standard) / 1.3 kg (deep)

Weight in water

0.02 kg (standard) / 0.75 kg (deep)

Pressure housing

Acetal copolymer (standard) / Titanium (deep)


Wavelength 700 nm
Sensitivity 0.013 NTU
Range, typical 0-25 NTU


Wavelength ex/em 470/695 nm
Sensitivity 0.025µg/I Chl
Range, typical 0-50µg/I Chl
Linearity (both) 99% R2


Digital output resolution 12 bit
RS-232 output 19200 baud
Analog output signal 0-5 V
Internal data logging optional
Internal batteries* optional
Connector MCBH6MP
Input 7-15 VDC
Current, typical 60 mA
Current, sleep 140µA
Data memory 90,000 samples
Sample rate to 8 Hz
Anti-fouling Bio-wiper™ optional


Temperature range 0 to 30 deg C
Depth rating standard 600 m
Depth rating with wiper* 300 m
Depth rating deep

6000 m

  • FLNTU(RT)— Analog and RS-232 serial output with 4,000-count range. Unit operates continuously when power is supplied.
  • FLNTU(RT)D—Provides the capabilities of the FLNTU(RT) with 6,000-meter depth rating.
  • FLNTUB—The capabilities of the FLNTU with internal batteries and memory for autonomous operation.
  • FLNTUS—The capabilities of the FLNTU with an integrated anti-fouling Bio-wiper™.
  • FLNTUSB—The capabilities of the FLNTUS with internal batteries for autonomous operation.

*The limit depth for ECO with Anti-fouling Bio-wiper™ and Internal Batteries (models B, S and SB) rated to 300 m.

Specifications are subject to change without notice. See product data sheet under documents tab for a download of this information,

Host software for ECO sensors.

Download ECOView 1.23

Released April 16, 2013
ECOView123.exe for Windows XP/Vista/7
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 Datasheet

ECO FLNTU datasheet

Monday, December 5, 2016

ECO with batteries product drawing

Tuesday, February 12, 2013

ECO real-time product drawing

Tuesday, February 12, 2013
Product Manual

ECO user manual (DE)

Tuesday, February 2, 2016
Product Manual

ECO user manual (EN)

Tuesday, February 2, 2016
Product Manual

ECO user manual (ES)

Tuesday, February 2, 2016
Product Manual

ECO user manual (FR)

Tuesday, February 2, 2016
Technical Note

Cable and Bulkhead Connector Maintenance

Thursday, March 9, 2017
Technical Note

ECO Battery Life Calculator

Wednesday, February 22, 2017
Technical Note

Instrument Voltage Ranges (in VDC)

Thursday, June 21, 2012
Technical Note

ECO Calibration Log Template

Wednesday, February 22, 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 is the fluorescent stick that came with my meter used for?

Checking Meter Output with the Fluorescent Stick

ECO meters ship with a stick of fluorescent material with which you can check your meter's output response.

  • With the meter on and outputting data, hold the stick approximately 1/2-in (1 cm) from the lit detectors. Be careful to NOT touch the sensor face, as it scratches easily.
  • Pivot the stick to parallel with the meter's optics; the output in the  meter's "signal" column should increase to near maximum output as given on the meter's characterization or calibration sheet.
  • As you move the stick away, the output will decrease.


How do I get started using my new ECO?

Please read more here.

What are device files and which one should I use?

Device files allow ECOView to provide processed data output where applicable. Please read more here.

How do I change the ASV resolution?

See the following Technical Note: Getting the Highest Resolution on your ECO_v1 [PDF]

Where can I recycle dead batteries?

Try Call2Recycle to recycle dead batteries.

Do you want WET Labs to review your data?

In order for data questions to be answered in an efficient manner, WET Labs requests:

-  The serial number of the instrument data in question. The most current calibration information
can be verified and the instrument settings upon delivery can be checked.

-  Description of the deployment configuration. Questions to consider:

  •   What are the current instrument settings?
  •   What is the instrument orientation?
  •   Are there possible obstructions?
  •   Is it being used in a mooring, a profiler, or being towed?
  •   What were the deployment date and geographical location?
  •   How far into the deployment was the problem seen?
  •   What power supply and cabling are being used?
  •   What was the instrument condition during the last field service or retrieval?
  •   Do you have any pictures?

-  Raw data files of the physical data in question

  •   examples of good raw data.
  •   examples of questionable raw data .

-  Information about how the raw data was processed.

How do I determine if my ECO firmware is G2 or G4?

Learn more...

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.

What should I use to lubricate the contacts on bulkhead connectors?

WET Labs recommends keeping the connectors on your meter lubricated using a good quality silicone spray lubricant, such as 3M Silicone Spray or Loctite 8021 spray. These can be purchased at your local hardware store. Avoid silicone grease. It is messy and attracts contaminants.

Do not use WD-40. It will destroy connectors.

How do I protect my ECO from bio-fouling?

ECO instruments from WET Labs are designed for long term deployment capabilities with low power requirements, a large memory and an available Bio-wiper™. The Bio-wiper™ on the ECO was designed to protect the optical surface and has been very effective under most conditions.

If extra protection is required to prevent marine organisms from attaching to the instrument body near the optical head and interfering with the operation of the Bio-wiper™ we suggest using copper foil tape. The GoMOOS project developed a technique for their ECO sensors and WET Labs recommends this technique:

Apply electrical tape under the area where copper tape will be applied. This protects the meter from the significant adhesive residue of the copper foil tape.

Apply the copper tape to the prepped surfaces. There are different width copper foil tape options, with non-conductive adhesive, available from McMaster-Carr. NOTE: when applying the coper tape, the adhesive should not be touched. This will cause the tape to not stick to the electrical tape on the meter. When submerged in salt water, the copper will adhere more closely to the meter.

As long as the electrical tape is used, this technique does not violate the ECO warranty and WET Labs will service instruments that have had copper tape applied to them.

Do NOT apply copper tape directly to the meter. Its adhesive is extremely difficult to remove. Meters returned to WET Labs wrapped in copper tape without the electrical tape preparation will have additional service charges applied.


What should I use to lubricate bulkhead connectors?

WET Labs recommends keeping the connectors on your meter lubricated using a good quality silicone spray lubricant, such as 3M Silicone Spray or Loctite 8021 spray. These can be purchased at your local hardware store. Avoid silicone grease. It is messy and attracts contaminants. 

Do not use WD-40. It will destroy connectors.