YSI 550A Specifications

Y S I Environmental

YSI 550A Dissolved Oxygen Instrument

Loaded with improved functionality

Looking for a rugged, field-worthy instrument for measuring dissolved

oxygen? e new YSI 550A DO instrument features a waterproof (IP-67),

impact-resistant case and innovative field-replaceable DO electrode

modules. Measure dissolved oxygen and temperature simultaneously

using YSI’s proven polarographic technology for oxygen and YSI Tem-

perature Precision™ thermistors, the planetwide standard for accuracy.

Our new PE membranes provide faster response times with less stir­ring dependence - saving time with every reading!

• Faster response time!

• Waterproof! Meets IP-67 specifications

• Field-replaceable DO electrode modules

Pure

Data

for a

Healthy

Planet.

Longest battery
life in the industry!

®

• Screw-on cap membranes

• PE membranes lessen stirring dependence!

• Over 2000 hours battery life

• Calibrate in either mg/L or % saturation

• User-selectable temperature units (°C or °F)

• 12, 25, 50 and 100-foot cable lengths

• Manual salinity input from 0 to 70 ppt

• ree-year instrument warranty,

one-year on the DO module!

Packed with features

Measurements are fast and easy with one-hand operation, an easy-to-use

backlit display, low-battery indicator, automatic push-button calibration, and

a weighted, quick-sinking probe. e YSI 550A DO has a built-in calibra-

tion chamber, direct salinity, temperature, and altitude compensation. e

instrument provides simultaneous readings of oxygen and temperature. DO

readings inlcude our expanded range of 0-50 mg/L!

www.YSI.com

Y S I Environmental

550A System Specifications (Instrument, Sensor, Cable)

To order, or for more
information, contact
YSI Environmental.

[phone]
800 897 4151 (US)

www.ysi.com

YSI Environmental
[phone]
Fax [phone]
[e-mail]

Endeco/YSI
[phone]
Fax [phone]
[e-mail]

SonTek/YSI
[phone]
Fax [phone]
[e-mail]

YSI Environmental Gulf Coast
[phone]
Fax [phone]
[e-mail]

YSI Hydrodata (UK)
[phone]
Fax [phone]
[e-mail]

YSI Middle East (Bahrain)
[phone]
Fax [phone]
[e-mail]

YSI (Hong Kong) Limited
[phone]
Fax [phone]
[e-mail]

YSI (Qingdao) Limited
[phone]
Fax [phone]
[e-mail]

YSI Nanotech (Japan)
[phone]
Fax [phone]

[e-mail]

ISO 9001
ISO 14001

Who’s Minding the Planet? and Pure
Data for a Healthy Planet are trade­marks of YSI Incorporated.

©2007 YSI Incorporated
Printed in USA 0107 W52-04

Range Resolution Accuracy

Dissolved Oxygen
% Saturation

Dissolved Oxygen
mg/L

Temperature

(°C or °F)

Medium Fresh, sea, or polluted water
Dissolved Oxygen Sensor Steady-state polarographic
Dissolved Oxygen Probe Field-replaceable module
Parameter Compensation Automatic temperature compensation for dissolved oxygen

Automatic salinity compensation (0-70 ppt) for dissolved
oxygen

Altitude compensation for calibration

Size 4.7 in. width; 9 in. length (11.9 cm x 22.9 cm)
Weight with batteries 2 lb. (0.91 kg)
Power 4 alkaline C cells
Battery Life Over 2000 hours at 25°C
Cables 12, 25, 50, or 100- foot lengths
Other Features Waterproof to IP-67

High-impact resistance

Push-button calibration

Built-in calibration chamber

Large, backlit display

Low battery indicator on display

Manual salinity input

CE compliance

Warranty 3-year for the instrument

1-year for the DO module

0 to 500% 0.1% air saturation or

0 to 50 mg/L 0.01 mg/L or 0.1 mg/L;

-5 to +45°C 0.1°C ±0.3°C

1%; selectable

selectable

0 to 200%: ±2% of reading or 2% air saturation,
whichever is greater; 200 to 500%: ±6% of
reading

0 to 20 mg/L: ± 0.3 mg/L or 2% of reading,
whichever is greater; 20 to 50 mg/L: ±6% of
reading

550A Ordering Information

550A-12, 25, 50 or 100 Instrument with 12, 25, 50 or 100-foot cable and probe

550A-12CC, 25CC, 50CC, or 100CC Instrument with 12, 25, 50 or 100-foot cable and probe
with carrying case

5908 Membrane kit, 1.25 mil PE (6 caps and bottle of KCl)

559 User-replaceable DO electrode

5085 Hands-free harness

5065 Form-fitted case with shoulder strap

5060 So-sided carrying case with storage

Y S I i n c o r p o r a t e d

Whoʼs Minding

the Planet?

™