YSI 6920 V2 Sonde

The YSI 6920 V2 sonde is an economical water quality logging system, ideal for long-term in situ monitoring and profiling.Real-time turbidity monitoring, dissolved oxygen monitoring, algae monitoring, and more.

  • Features
  • Specifications
  • Video

The sonde comes in two versions:

  • 6920 V2-1 has 1 optical port, 1 conductivity/temperature port, 1 Rapid Pulse Dissolved Oxygen port, 1 pH/ORP port, and 3 ISE ports
  • 6920 V2-2 has 2 optical ports, 1 conductivity/temperature port, 1 pH port, and 1 ISE port

Available optical sensors:

  • ROX optical dissolved oxygen
  • Blue-green algae
  • Chlorophyll
  • Turbidity
  • Rhodamine

A pressure sensor is an option on both versions.

Additional parameters include:

  • Salinity
  • Specific Conductance
  • Depth or Shallow Vented Level
  • TDS
  • Open-channel Flow
  • Nitrate-nitrogen, Ammonia/Ammonium-nitrogen, or Chloride (ISEs)

This product features:

  • Field-replaceable sensors
  • Choice between one or two optical sensor ports
  • Self-cleaning optical sensors and anti-fouling components for extended deployment
  • RS-232 and SDI-12 communications
  • Battery power for long-term deployments

The 6920 V2-2 has:

  • 2 optical ports
  • Conductivity/temperature port
  • pH or pH/ORP port
  • ISE port
General Sonde Specifications 
Medium Fresh, sea or polluted water
Temperature - Operating -5 to +50°C
Temperature - Storage -10 to +60°C
Communications RS-232, SDI-12
Software EcoWatch®
Diameter 2.85 in, 7.24 cm
Length 18 in, 45.7 cm
Weight 4 lbs, 1.8 kg
Power - External 12 V DC
Power - Internal 8 AA-size alkaline batteries
Certifications CE, EU Battery Compliance, FCC, IP-67, WEEE, and MCERTS; Assembled in the USA

Sensor SpecificationsRangeResolutionAccuracy
ROX™
Optical Dissolved Oxygen•
% Saturation
0 to 500% 0.1% 0 to 200%: ±1% of reading or 1% air saturation, whichever is greater;
200 to 500%: ±15% of reading
ROX™
Optical Dissolved Oxygen•
mg/L
0 to 50 mg/L 0.01 mg/L 0 to 20 mg/L: ± 0.1 mg/L or 1% of reading, whichever is greater;
20 to 50 mg/L: ±15% of reading
Conductivity••
6560 Sensor‡​
0 to 100 mS/cm 0.001 to 0.1 mS/cm
(range dependent)
±0.5% of reading + 0.001 mS/cm
Salinity 0 to 70 ppt 0.01 ppt ±1% of reading or 0.1 ppt,
whichever is greater
Temperature
6560 Sensor‡​
-5 to +50°C 0.01°C ±0.15°C
pH
6561 Sensor‡​
0 to 14 units 0.01 unit ±0.2 unit
ORP -999 to +999 mV 0.1 mV ±20 mV
Depth - Deep 0 to 656 ft, 200 m 0.001 ft, 0.001 m ±1 ft, ±0.3 m
Depth - Medium 0 to 200 ft, 61 m 0.001 ft, 0.001 m ±0.4 ft, ±0.12 m
Depth - Shallow 0 to 30 ft, 9.1 m 0.001 ft, 0.001 m ±0.06 ft, ±0.02 m
Vented Level 0 to 30 ft, 9.1 m 0.001 ft, 0.001 m ±0.01 ft, 0.003 m
Turbidity•
6136 Sensor‡
0 to 1,000 NTU 0.1 NTU ±2% of reading or 0.3 NTU,
whichever is greater**
Nitrate / nitrogen••• 0 to 200 mg/L-N 0.001 to 1 mg/L-N
(range dependent)
±10% of reading or 2 mg/L,
whichever is greater
Ammonium / ammonia /
nitrogen•••
0 to 200 mg/L-N 0.001 to 1 mg/L-N
(range dependent)
±10% of reading or 2 mg/L,
whichever is greater
Chloride••• 0 to 1000 mg/L 0.001 to 1 mg/L
(range dependent)
±15% of reading or 5 mg/L,
whichever is greater
Rhodamine• 0-200 μg/L 0.1 μg/L ±5% reading or 1 μg/L,
whichever is greater

Blue-Green Algae Sensor SpecificationsRangeDetection LimitResolutionLinearity
Blue-Green Algae
Phycocyanin•
~0 to 280,000 cells/mL†
0 to 100 RFU
~220 cells/mL§ 1 cell/mL
0.1 RFU
R2 > 0.9999**
Blue-Green Algae
Phycoerythrin•
~0 to 200,000 cells/mL†
0 to 100 RFU
~450 cells/mL§§ 1 cell/mL
0.1 RFU
R2 > 0.9999***
Chlorophyll•
6025 Sensor‡​
~0 to 400 μg/L
0 to 100 RFU
~0.1 μg/L§§§ 0.1 μg/L Chl
0.1% RFU
R2 > 0.9999****

• Maximum depth rating for optical probes is 200 feet, 61 m. Turbidity, Rhodamine, Blue-Green Algae (PC & PE) and Chlorophyll are available in a Deep Depth option (0 to 200 m). Anti-fouling optical probes have depth rating of 200 m.
•• Report outputs of specific conductance (conductivity corrected to 25° C), resistivity, and total dissolved solids are also provided. These values are automatically calculated from conductivity according to algorithms found in Standard Methods for the Examination of Water and Wastewater (ed 1989).
••• Freshwater only. Maximum depth rating of 50 feet, 15.2 m. 600 V2-2 has 3 ISE ports; not available on the 6600V2-4.

*In YSI AMCO-AEPA Polymer Standards.
**For serial dilution of Rhodamine WT (0-400 ug/L).
***For serial dilution of Rhodamine WT (0-8 μg/L).
****For serial dilution of Rhodamine WT (0-500 ug/L).

RFU = Relative Fluorescence Units ​
† Explanation of Ranges can be found in the 'Principles of Operation' section of the 6-Series Manual, Rev D.
‡​ Sensors with listed with ETV logo were submitted to the U.S. EPA ETV program on the YSI 6600EDS. Information on performance characteristics of YSI water quality sensors can be found at www.epa.gov/etv, or call YSI at 800.897.4151 800.897.4151 for the ETV verification report. Use of ETV name or logo does not imply approval or certification of this product nor does it make any explicit or implied warranties or guarantees as to product performance.

§ Estimated from cultures of Microcystis aeruginosa.
§§ Estimated from cultures Synechococcus sp.
§§§ Determined from cultures of Isochrysis sp. and chlorophyll a concentration determined via extractions.

Specifications indicate typical performance and are subject to change.

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