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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...
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The YSI 550A DO Instrument is designed for field use and is available with cable lengths of 12, 25, 50, or 100 feet (3.5, 7.5, 15, 30.5 meters). The body of the probe has been manufactured with stainless steel to add rugged durability and sinking weight.
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DO Instrument should ever need repair. WARRANTY The YSI 550A DO Instrument is warranted for three years from date of purchase by the end user against 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.
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Enter Key Button for execution of commands. BATTERIES The YSI 550A DO Instrument is powered by 4 C-size alkaline batteries. A new set of alkaline batteries will provide approximately 2000 hours of continuous operation. When batteries need to be replaced, the LCD will display a "LO BAT"...
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The wet sponge creates a 100% water saturated air environment for the probe. This environment is ideal for dissolved oxygen calibration and for storage of the probe during transport and non-use. The YSI 550A DO Instrument’s storage chamber can be conveniently used from either side of the instrument. SMALL HOLE Remove the chamber from the FOR STOPPER’S...
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PREPARING THE PROBE MEMBRANE CAP INSTALLATION The YSI 550A DO probe is shipped with a dry, protective membrane. Before using the instrument for the first time, remove the protective cap and replace it with a new one following these instructions: Remove the probe sensor guard to access the probe tip.
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DISSOLVED OXYGEN CALIBRATION Dissolved oxygen calibration must be done in an environment with known oxygen content. The YSI 550A DO Instrument can be calibrated in either mg/L or % saturation. Sections below include instructions on how to calibrate in either mode.
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2. Use the UP ARROW and DOWN ARROW keys to adjust the salinity value to that of the samples you will be measuring, 0-70 ppt. 3. Press the ENTER key to save the calibration. 4. Press Mode to return to dissolved oxygen measurement Environmental Y S I YSI 550A Page 7...
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PROBE OPERATION NOTE: The YSI 550A DO Instrument should not be used in a purpose other than that specified by YSI Incorporated. See Warranty for details. STIRRING It is important to recognize that a very small amount of oxygen dissolved in the sample is consumed during probe operation.
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For correct probe operation, the gold cathode must be textured properly. It can become tarnished or plated with silver after extended use. The gold cathode can be cleaned by using the YSI 5238 Probe Reconditioning Kit or 400 grit wet/dry sandpaper. Never use chemicals or abrasives not recommended or supplied by YSI.
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DO sensor module. Also, if the hex screw was removed completely, make sure that it is not cross-threaded when replaced. The YSI 559 DO module is shipped with a dry, protective membrane. Before using for the first time, remove the protective cap and replace it with a new one following the instructions for Membrane Cap Installation.
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12, 25, 50, and 100-foot lengths (3.5, 7.5, 15, 30.5 meter lengths) Other Features: Waterproof to IP-67 High-impact resistance Push-button calibration Built-in calibration chamber Large back-lit display Low battery indicator on display Manual salinity input CE-compliance Environmental Y S I YSI 550A Page 11...
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A. Sample temperature is less than -5º C (23ºF) or more than "Ovr" or “Undr”. C (122 F). Increase or decrease the sample temperature to bring within the allowable range. B. Return system for service. Environmental Y S I Page 12 YSI 550A...
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“EEP” CONTACT INFORMATION YSI offers a wide range of customer assistance and technical support functions to ensure that you have the information required to use our products. Contact YSI Environmental if you need assistance or have questions regarding any YSI Environmental Product. Business hours are Monday through Friday, 8AM to 5PM ET.
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Note: While testing to EN-61000-4-6, Conducted RF Immunity, per Table A.1 of EN61326, Electrical Equipment for Measurement, Control and Laboratory Use, the YSI 550A exhibited an ERROR 8 message from 8.6 MHz 22.8 MHz at induced RF voltages of 3- Volts to 1-Volt RMS on the 25-foot probe cable.
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