YSI 550A User Manual

YSI 550A

Dissolved Oxygen Instrument

Operations
Manual

CONTENTS

CONTENTS.................................................................................................................................................iii

GENERAL DESCRIPTION ......................................................................................................................1

WARRANTY................................................................................................................................................2

FEATURES OF THE YSI 550A................................................................................................................3

PRINCIPLES OF OPERATION...............................................................................................................5

PREPARING THE PROBE.......................................................................................................................5

DISSOLVED OXYGEN CALIBRATION...............................................................................................6

SALINITY COMPENSATION CALIBRATION ..................................................................................7

PROBE OPERATION ................................................................................................................................8

PROBE ELECTRODE MAINTENANCE ..............................................................................................9

ACCESSORIES/REPLACEMENT PARTS.........................................................................................10

SPECIFICATIONS....................................................................................................................................11

TROUBLESHOOTING............................................................................................................................12

CONTACT INFORMATION..................................................................................................................13

REQUIRED NOTICE...............................................................................................................................14

YSI 550A Y S I Environmental iii

GENERAL DESCRIPTION

The YSI 550A Handheld Dissolved Oxygen Instrument is a rugged, microprocessor based, digi tal
instrument with a field-replaceable YSI dissolved oxygen probe. The YSI 550A DO Instrument is
impact-resistant and waterproof.

The YSI 550A DO Instrument is designed for field use and is available wi th cable lengt hs of 12, 25, 50,
or 100 feet (3.5, 7.5, 15, 30.5 meters). The body of the probe has been manufactured with stainl ess steel
to add rugged durability and sinking weight. The large Liquid Crystal Display (LCD) is easy to read and
is equipped with a backlight for use in dark or poorly lighted areas.

The YSI 550A DO Instrument can be easily calibrated with the press of a few keys. Addit ionally, t he
instrument’s microprocessor performs a self-diagnostic routine each time the instrum ent is turned on.
The self-diagnostic routine provides you with useful informat ion about the funct ion of the instrum ent
circuitry and the quality of the readings you obtain.

The system displays temperature in either
liter) or % air saturation. The system requires only a single calibration regardless of which dissolved
oxygen display is used, and will calibrate in either mode. Salinity compensation values can be changed
at any time without performing a new calibrat ion.

A detachable calibration chamber is mounted to the back of the inst rument . A smal l sponge in the
chamber can be moistened to provide a water saturated air environm ent that i s ideal for air cali bration.
This chamber is also designed for transporting and storing the probe. When the probe is stored in the
chamber, the moist environment will prolong effective membrane perform ance and probe life.

The YSI 550A DO Instrument is powered by 4 C-size alkaline batteries. A new set of alkal ine batteri es
will provide approximately 2000 hours of continuous operation. If the backlight is used often, batteries
will be depleted faster.

The YSI 550A case is waterproof with an IP-67 rating. The instrument is 100% corrosion proof and can
be operated in a wet environment without damage to t he instrum ent.

INITIAL INSPECTION

When you unpack your new YSI 550A DO Handheld Instrument for the first time, check t he packing
list to make sure you have received everything. If there is anything missing or damaged, call the dealer
from whom you purchased the YSI 550A. If you do not know which authorized dealer sold t he system
to you, call YSI Customer Service at 800-897-4151 or 937-767-7241.

o

C or oF and dissolved oxygen in either mg/L (milligrams per

YSI 550A Y S I Environmental Page 1

WARRANTY REGISTRATION

Please complete the Product Registration on the YSI website at
you may complete the Warranty Card included with your instrument and return it to YSI Incorporated.
Your purchase of this quality instrument will then be recorded in YSI’s customer database. Once your
purchase is recorded, you will receive prompt, efficient service in the event any part of your YSI 550A
DO Instrument should ever need repair.

www.ysi.com. If you are not online,

WARRANTY

The YSI 550A DO Instrument is warranted for three years from date of purchase by t he end user agai nst
defects in materials and workmanship. YSI 550A DO probes and cables are warranted for one year from
date of purchase by the end user against defects in material and workmanship. Within the warranty
period, YSI will repair or replace, at its sole discretion, free of charge, any product that YSI determines
to be covered by this warranty.

To exercise this warranty, write or call your local YSI representative, or contact YSI Customer Service
in Yellow Springs, Ohio. Send the product and proof of purchase, transportation prepaid, to the
Authorized Service Center selected by YSI. Repair or replacement will be made and the product
returned, transportation prepaid. Repaired or replaced products are warranted for the balance of the
original warranty period, or at least 90 days from date of repair or replacement.

Limitation of Warranty

This Warranty does not apply to any YSI product damage or failure caused by (i) failure to install,
operate or use the product in accordance with YSI’s written instructions, (ii) abuse or misuse of the
product, (iii) failure to maintain the product in accordance with YSI’s written instructions or standard
industry procedure, (iv) any improper repairs to the product, (v) use by you of defective or improper
components or parts in servicing or repairing the product, or (vi) modification of the product in any way
not expressly authorized by YSI.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED,
INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE. YSI’s LIABILITY UNDER THIS WARRANTY IS LIMITED TO REPAIR OR
REPLACEMENT OF THE PRODUCT, AND THIS SHALL BE YOUR SOLE AND EXCLUSIVE
REMEDY FOR ANY DEFECTIVE PRODUCT COVERED BY THIS WARRANTY. IN NO
EVENT SHALL YSI BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR
CONSEQUENTIAL DAMAGES RESULTING FROM ANY DEFECTIVE PRODUCT COVERED
BY THIS WARRANTY.

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