YSI 55 User Manual

YSI Model 55
Handheld Dissolved Oxygen and Temperature System
Table of Contents
1. General Description ......................................................................................................1
2. Specifications ................................................................................................................2
3. Preparing The Meter .....................................................................................................3
3.1. Unpacking.........................................................................................................................3
3.2. Warranty Card ..................................................................................................................3
3.3. Batteries ............................................................................................................................3
3.4. Calibration/Storage Chamber...........................................................................................4
3.5. Hand Strap ........................................................................................................................4
3.6. The Meter Case.................................................................................................................4
4. Preparing The Probe.....................................................................................................5
4.1. Description........................................................................................................................5
4.2. Choosing The Right Membrane.......................................................................................5
4.3. Probe Preparation..............................................................................................................5
4.4. Membrane Installation......................................................................................................6
4.5. Probe Operation and Precautions.....................................................................................7
5. Calibration......................................................................................................................8
5.1. Before You Calibrate........................................................................................................8
5.2. The Calibration Process....................................................................................................8
6. Principles Of Operation................................................................................................10
6.1. Discussion Of Measurement Errors.................................................................................10
7. Troubleshooting............................................................................................................12
8. Warranty And Repair ....................................................................................................14
8.1. Cleaning Instructions........................................................................................................15
8.2. Packing Instructions .........................................................................................................16
9. Required Notice.............................................................................................................17
10. Accessories And Replacement Parts .......................................................................18
11. Appendix A - Solubility Table ....................................................................................19
12. Appendix B - Conversion Chart ................................................................................21
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1. General Description
The YSI Model 55 Handheld Dissolved Oxygen System is a rugged, micro-processor based, digital meter with an attached YSI dissolved oxygen probe.
The YSI Model 55 is designed for field use and is available with cable lengths of 12, 25 or 50 feet. The body of the probe has been manufactured with stainless 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 Model 55's micro-processor allows the system to be easily calibrated with the press of a few keys. Additionally, the micro-processor performs a self-diagnostic routine each time the instrument is turned on. The self-diagnostic routine provides you with useful information about the function of the instrument circuitry and the quality of the readings you obtain. For a list of these diagnostic features, see chapter 7 Troubleshooting.
The system simultaneously displays temperature in (milligrams per liter) or % air saturation. The system requires only a single calibration regardless of which dissolved oxygen display you use. You can switch back and forth from % air saturation to mg/L with a single push of the MODE key.
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A calibration chamber is built into the instrument. A small sponge in the chamber can be moistened to provide a water saturated air environment which is ideal for air calibration. 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 performance and probe life.
The instrument is powered by six AA-size alkaline batteries. A new set of alkaline batteries will provide approximately 100 hours of continuous operation. When batteries need to be replaced, the LCD will display a "LO BAT" message.
The YSI Model 55 instrument case is splash resistant. You can operate your Model 55 in a steady rain without damage to the instrument.
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2. Specifications
Probe Operating Environment
Medium: fresh, sea, or polluted water Temperature: -5 to +45
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Depth: 0 to 12, 0 to 25 or 0 to 50 feet (depending on cable length)
Meter Ambient Operating/Storage Temperature: -10 to +50
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Material: ABS, Stainless Steel, Acrylic, and other materials.
Dimensions:
Height: 9.5 inches (24.13 cm) Thickness: 2.2 inches (5.6 cm) Width: 3.5 inches max. ( 8.89 cm) Weight: 1.7 pounds ( 0.77 kg)
Power: 9 VDC - 6 AA-size Alkaline Batteries (included)
Approximately 100 hours operation from each new set of batteries
Water Tightness: Meets or exceeds IP65 standards
Extensive testing of the YSI Model 55 suggests the following typical performance:
Temperature
Sensor Type................Thermistor
Range..........................-5 to +45
Accuracy ....................± 0.2
Resolution ..................0.1
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Dissolved Oxygen % Saturation
Sensor Type................Membrane covered polarographic
Range..........................0 to 200 % air saturation
Accuracy ....................± 2 % air saturation
Resolution ..................0.1 % air saturation
Dissolved Oxygen mg/L
Sensor Type................Calculated from % air saturation, temperature and salinity.
Range..........................0 to 20 mg/L
Accuracy ....................± 0.3 mg/L
Resolution ..................0.01 mg/L
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3. Preparing The Meter

3.1. Unpacking
When you unpack your new YSI Model 55 Handheld Dissolved Oxygen System for the first time, check the packing list to make sure you have received everything you should have. If there is anything missing or damaged, call the dealer from whom you purchased the Model 55. If you do not know which of our authorized dealers sold the system to you, call YSI Customer Service at 800-765­4974 or 937-767-7241, and we'll be happy to help you.
3.2. Warranty Card
Before you do anything else, please complete the Warranty Card and return it to YSI. This will record your purchase of this quality instrument in our computer system. Once your purchase is recorded, you will receive prompt, efficient service in the event any part of your YSI Model 55 should ever need repair.
3.3. Batteries
There are a few things you must do to prepare your YSI Model 55 for use. First, locate the six AA-size alkaline batteries which were included. Use a screwdriver or a small coin to remove the thumbscrew on the bottom of the instrument. This thumbscrew holds the battery­chamber cover in place. The battery-chamber cover is marked with the words "OPEN" and "CLOSE."
O-RING
HAND STRAP
POLARITY LABEL
NOTE: On some models, the battery cover
BATTERY CHAMBER LID
thumbscrew may be unscrewed by hand (a screwdriver may not be required).
There is a small label inside each of the two battery-chamber sleeves. These labels illustrate the correct way to install the batteries into each sleeve of the battery-chamber.
NOTE: It is very important that the batteries be installed ONLY as illustrated. The instrument
will not function if the batteries are installed incorrectly.
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Turn the instrument on by pressing and releasing the ON/OFF button on the front of the instrument. The instrument will activate all segments of the display for a few seconds, which will be followed by a self test procedure which will last for several more seconds. During this power on self test sequence, the instrument’s microprocessor is verifying that the instrument is working. If the instrument were to detect a problem, a continuous error message would be displayed. If the instrument does not operate, consult chapter 7 Troubleshooting.
NOTE: The information on the display will be meaningless since the probe has not yet been prepared.
You may also want to take the instrument into a dark room and, with the instrument ON, hold down the LIGHT key. The instrument back-light should illuminate the LCD so that the display can be easily read.
3.4. Calibration/Storage Chamber
The Model 55 has a convenient calibration/storage chamber built into the instrument’s side. This chamber provides an ideal storage area for the probe during transport and extended non-use. If you look into the chamber, you should notice a small round sponge in the bottom. Carefully put 3 to 6 drops of clean water into the sponge. Turn the instrument over and allow any excess water to drain out of the chamber. The wet sponge creates a 100% water saturated air environment for the probe which is ideal for dissolved oxygen calibration.
CALIBRATION CHAMBER
3.5. Hand Strap
The hand strap is designed to allow comfortable operation of the Model 55 with minimum effort. If the hand strap is adjusted correctly, it is unlikely that the instrument will be easily dropped or bumped from your hand.
To adjust the hand strap on the back of the meter, unsnap the leather cover and pull the two Velcro strips apart. Place your hand between the meter and the strap and adjust the strap length so that your hand is snugly held in place. Press the two Velcro strips back together and snap the leather cover back into place.
3.6. The Meter Case
The meter case is sealed at the factory and is not intended to be opened, except by authorized service technicians. Do not attempt to separate the two halves of the meter case as this may damage the instrument, break the water-proof seal, and may void the manufacturer's warranty.
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