YSI Model 52 Dissolved Oxygen Meter Operations Manual
CONTENTS SECTION 1 INTRODUCTION ................................................................................................................. 1 1.1 1.2 1.3 1.4 PRINCIPLES OF OPERATION ...................................................................................................... 1 DISPLAY AND FUNCTION KEYS ............................................................................................... 2 FUNCTION SWITCH ..............................................................................
AUTHORIZED U.S. SERVICE CENTERS............................................................................................ 32 CLEANING INSTRUCTIONS ............................................................................................................... 34 PACKING INSTRUCTIONS.................................................................................................................. 34 APPENDIX A GENERAL SPECIFICATIONS............................................................................
SECTION 1 INTRODUCTION The YSI Model 52 is a microprocessor-based instrument designed for field and laboratory measurement of dissolved oxygen. Readings are automatically compensated for temperature. When calibrated to percent air saturation, the display simultaneously shows dissolved oxygen in mg/L and in percent air saturation as well as temperature in degrees Celsius. An RS232 port permits results to be sent directly to your serial printer or personal computer.
Introduction 1.2 Section 1 DISPLAY AND FUNCTION KEYS A rotary function switch and four keys provide complete control of the Model 52. The four keys are SKIP,¿ ,À , and CONFIRM. ¿ andÀ are used to modify a setting either up or down (for example, calibration or salinity values can be modified for each calibration process if required). The CONFIRM key is used to accept your setting. The display often asks questions such as “Calibrate in percent?” Use CONFIRM to answer yes.
SECTION 2 PREPARING THE METER To prepare the meter for use, connect a prepared probe to the meter. Set the function switch to O2-TEMP. Observe temperature and oxygen readings for stability, or set up Autostable. Since complete equilibration can take as long as 15 minutes after the meter is turned on, it is customary to leave the instrument on throughout the working day. When the instrument is turned on, a beep signals the beginning of a Power On Self Test (POST). A series of displays will appear.
Preparing the Meter YSI, Incorporated Section 2 Model 52 4
SECTION 3 CALIBRATION Calibration is accomplished by exposing the probe to a known concentration of oxygen and then adjusting the calibration value to match. Since the oxygen content of our atmosphere varies predictably according to relative humidity and atmospheric pressure, we recommend that you calibrate in air, see Section 3.3, Calibration in Air. Daily calibration is usually appropriate.
Calibration 3.3 Section 3 CALIBRATION IN AIR Three separate calibration techniques are discussed here: calibration in air, calibration in air-saturated water, and calibration by Winkler titration. Choose the one technique which best fits your application. Calibration in air is the simplest and most accurate method of calibration. To calibrate in air: 1. Place a prepared probe in air at 100% relative humidity. To achieve this, BOD probes can be placed in a BOD bottle with approximately 1” of water.
Calibration Section 3 4. When you have adjusted the reading to the desired value (let’s say you chose 98.0%), press CONFIRM. The instrument will display the legend “Please wait” for a few seconds. Then it will display: Calibrated to 9 8. 0 % You are now ready to measure dissolved oxygen. 3.4 CALIBRATION IN AIR-SATURATED WATER A second alternative for calibration is to calibrate in air-saturated water.
Calibration Section 3 3. Switch to CALIBRATE. The display will read: Calibrate in percent? Press SKIP. The display will read: Calibrate in mg/L? Press CONFIRM to select mg/L calibration. A display similar to the one below will be shown. Enter cal value Last = 8.15 mg/ L 4. Use ¿ and À to set the calibration value determined by Winkler titration. You may be able to set the value more quickly by using the SKIP key to bring the value near the one you want, then continuing with ¿ and À.
Calibration Section 3 5900 Series probes. This is the default zero value. Although using this average will result in errors with probes whose background current differs from the average. Note: Errors will be insignificant in most applications. See Discussion of Measurement Errors. For highest accuracy measurements, a zero calibration should be performed to compensate for the specific background current of the probe in use.
Calibration Section 3 Note: When you change the zero calibration point, you offset the other value, so that after zeroing the probe for zero oxygen, you must recalibrate in an oxygen environment. If you try to take readings without recalibrating, the display will provide this warning: 8.74mg/L Recalibrate 25.6C You may also select mg/L calibration and then zero-calibrate and the result will be the same. 3.
SECTION 4 SALINITY Salt reduces the ability of water to hold oxygen in solution. Enter the salinity of the sample you are measuring, and the meter will automatically compensate for the effect of salinity on dissolved oxygen. The default salinity setting is 0.0 ppt. You can enter any salinity setting between 0.0 and 40.0 ppt. To do this, turn the function switch to SALINITY. A display similar to the one below will show: Enter salinity Setting = 0.0 Use ¿ and À to adjust the salinity setting.
Salinity Section 4 Even if your sample is saline, it is still best to calibrate in air. However, if you must calibrate in air-saturated water, it is best if the calibration sample is similar to the sample you intend to measure. Disregard the mg/L reading when measuring non-aqueous liquids. Such samples may have an oxygen solubility or Bunsen coefficient significantly different from those used in the Model 52. Note: If you are calibrating in mg/L, the salinity must be set before calibration.
SECTION 5 OPERATION 5.1 TEMPERATURE MEASUREMENTS Allow 3 to 5 minutes for temperature equilibration, and then take the temperature reading. 5.2 DISSOLVED OXYGEN MEASUREMENTS While the selector switch is set to O2-TEMP, place the prepared probe in the sample to be measured. Allow 3 to 5 minutes for temperature equilibration, or wait for the * to display if using the autostable feature. Begin stirring at least 30 seconds before taking readings. Observe readings for stability and record measurements.
Operation 5.4 Section 5 RECORDING TO INTERNAL MEMORY The Model 52 has several functions available while the function switch is set to “O2Temp.” Use the arrow keys to see the following menu options.
Operation Section 5 To activate the Memory feature of the YSI Model 52, press the À key while the function switch is set to O2-TEMP. A display similar to the following will appear: 7.0mg/L 23.4C Recording Mode? Press the CONFIRM key to enter Recording Mode. A display similar to the following will appear: 7.0mg/L R:1 23.4C 14:59 To record a reading now, press CONFIRM. The message “Data Stored” will flash across the display.
Operation 5.6 Section 5 PRINTING DATA FROM MEMORY To send all data from the YSI Model 52 memory to a serial printer, attach the RS232 Cable (supplied) to the Model 52 and your printer. With the function switch set to O2TEMP press the À key repeatedly until a display similar to the following appears: 7.0mg/L 23.4C Print Data? Press the CONFIRM key. All of the data currently stored in the Model 52 memory will be sent to your printer. Note: There is no way to send individual records from memory.
Operation 5.8 Section 5 ERASING THE MODEL 52 MEMORY To erase the entire memory of the Model 52, set the function switch to O2-TEMP and press the À key until a display similar to the following appears: 7.0mg/L 23.4C Erase Memory? Caution: All data stored in memory will be lost forever! Press CONFIRM while the above display is visible. A display similar to the following will appear: Erase Data? No If you do not wish to erase all of the Model 52 memory, press confirm now.
SECTION 6 SYSTEM SETUP 6.1 SETTING THE TIME AND DATE It is especially important to assure that the date and time have been correctly set when using a PC or the Model 52 memory to record readings. When using either of these features the Model 52 will also record the date and time of each reading. Set the function switch to SYSTEM SETUP. The first display will read: Setup clock/calendar? Press CONFIRM.
System Setup Section 6 To set the autostable criteria, set the function switch to SYSTEM SETUP. Press the SKIP button repeatedly until the following display appears: Setup autostable? Press the CONFIRM button. The following display will appear: Setup autostbl on/off Press the CONFIRM button. The following display will appear: Setup autostbl = off Use either arrow key to select ON, then press CONFIRM. The following display will appear: Setup change in %? Press CONFIRM.
System Setup Section 6 Use the arrow keys to select the desired autostable % (the smaller the %, the more accurate your reading and the more time it will take to achieve). Press CONFIRM. The following display will appear: Setup # of rdgs? Press CONFIRM. The following display will appear: Setup # of rdgs = 5 Use the arrow keys to select the # of readings which must pass while complying with the % change entered previously. (The larger the #, the greater the accuracy and the longer it will take.) 6.
System Setup Section 6 Press CONFIRM to select communications setup. The following display will appear: Setup baud rate? Use SKIP to go on to the next choice, or press CONFIRM to change the baud rate. If you pressed CONFIRM, you would see: Setup baud rate= 9600 Use ¿ to increase the baud rate and À to decrease it. The Model 52 supports 110, 300, 1200, 2400, 4800, and 9600 baud and defaults to 9600. When you have selected the correct baud rate, press CONFIRM to enter the value.
System Setup Section 6 Setup LCD Contrast? Press the CONFIRM key to select the contrast setup. The following display will appear: LCD Contrast HI LOW Press the ¿ key to increase the contrast (lighten the display background). Press theÀ key to decrease the contrast (darken the display background).
SECTION 7 PERSONAL COMPUTER INTERFACE The RS232 port allows you to connect your Model 52 meter directly to an IBM compatible personal computer (PC). Your PC can then gather, store and analyze the dissolved oxygen data generated by the meter. The system includes an RS232 cable. We recommend that you use a commercially available communication software product to interface the Model 52 to your PC. Some of the products that will work are CROSSTALK™, ProComm™, and PC Talk™.
Personal Computer Interface YSI, Incorporated Section 7 Model 52 24
SECTION 8 MAINTENANCE AND TROUBLESHOOTING 8.1 BATTERIES Low batteries are indicated in the display by an arrow pointing to LO BATT, as shown here LO BATT Å 7.92mg/L 86.0% 22.5C 14:15 When this happens, replace the batteries with 6 fresh alkaline batteries as soon as possible. Remove the 4 case screws from the back of the meter and carefully lift the back cover away from the rest of the meter. The battery pack is attached to the back cover. Insert three fresh alkaline batteries into each tube.
Maintenance and Troubleshooting Section 8 CODE E. 0 ERROR System error CAUSE Defective ROM CORRECTION Return for service E.00 Lost calibration value Defective RAM backup Return for service battery E.01 Defective RAM Defective RAM Return for service E .
SECTION 9 DISCUSSION OF MEASUREMENT ERRORS The major sources of error in DO measurement are the accuracy of the instrument components, the accuracy of the probe, and the user’s ability to calibrate the system precisely. Most errors can be reduced substantially by calibrating at DO levels and probe temperatures as close as possible to the expected measurement of DO levels and temperatures. In the following, individual sources of error and their ranges are listed.
Discussion of Measurement Errors Section 9 2. Probe nonlinearity error: ±0.3% of reading 3. The variation from nominal response to sample temperature is ±0.2% of the DO reading per degree C of the temperature difference between the temperature of the sample and the temperature at which the probe was calibrated. 9.3 TYPE 3 ERRORS - CALIBRATION 1.
Discussion of Measurement Errors Section 9 Calculation TYPE 1a 2a 2b 2c 3a 3b 3c DESCRIPTION instrument accuracy probe background probe nonlinearity temp. compensation temp. uncertainty pressure altitude CALCULATION ±0.001 x 8.24 + 0.01 ±0.01 x (1-8.24/9.07) x 7.26 ±0.003 x 7.26 ±(24-20) x 0.002 x 7.26 ±0.01 x 7.26 ±0.017 x 7.26 ±0.018 x 7.26 ERROR(mg/L) ±0.02 ±0.01 ±0.02 ±0.06 ±0.07 ±0.12 ±0.13 Probable error can be determined by an r.m.s. calculation: r.m.s. error = [.022 + .012 + .022 + .062 + .
Discussion of Measurement Errors YSI, Incorporated Section 9 Model 52 30
SECTION 10 WARRANTY AND REPAIR YSI Model 52 Dissolved Oxygen Meters are warranted for two years from date of purchase by the end user against defects in materials and workmanship. YSI probes, cables and sensors 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.
Warranty and Repair Section 10 AUTHORIZED U.S. SERVICE CENTERS For information on the closest Authorized Service Center contact: YSI Technical Support • 1725 Brannum Lane • Yellow Springs, Ohio 45387 Phone: +1 (937) 767-7241 • 800 897-4151 • Email: environmental@ysi.com • www.ysi.
Warranty and Repair YSI, Incorporated Section 10 Model 52 33
Warranty and Repair Section 10 CLEANING INSTRUCTIONS NOTE: Before they can be serviced, equipment exposed to biological, radioactive, or toxic materials must be cleaned and disinfected. Biological contamination is presumed for any instrument, probe, or other device that has been used with body fluids or tissues, or with waste water. Radioactive contamination is presumed for any instrument, probe or other device that has been used near any radioactive source.
Warranty and Repair Section 10 Cleaning Certificate Organization Department Address City _______________ State ______ Zip Country __________________ Phone Model No.
Warranty and Repair YSI, Incorporated Section 10 Model 52 36
APPENDIX A GENERAL SPECIFICATIONS Oxygen Measurement Ranges: Accuracy: Resolution: 0.0 to 19.99 mg/L dissolved oxygen 0.0 to 199.9% air saturation ±0.1% of saturation value, plus 1 Least Significant Digit for mg/L readings, plus probe error ±0.1% of air saturation, plus 1 Least Significant Digit for % readings, plus probe error 0.1% of the saturation value, expressed in mg/L, or 0.01 mg/L , whichever is greater; 0.1% air saturation Temperature Measurement Range: Accuracy: Resolution: -5.0 to +45.
General Specifications Appendix A Power The Model 52 is powered by 6 alkaline D-cells batteries, or an AC adapter (optional). Batteries power the instrument for approximately 100 hours. Size and Weight 21.6 by 28 by 9.5 cm; 2.4 kg 8.5 by 11 by 3.75 inches; 4.
APPENDIX B REQUIRED NOTICE The Federal Communications Commission defines this product as a computing device and requires the following notice. This equipment generates and uses radio frequency energy and if not installed and used properly, may cause interference to radio and television reception. There is no guarantee that interference will not occur in a particular installation.
Required Notice YSI, Incorporated Appendix B Model 52 40
APPENDIX C OXYGEN SOLUBILITY Solubility of oxygen in mg/L in water exposed to water-saturated air at 760 mm Hg pressure. Temp °C 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 17.0 18.0 19.0 20.0 21.0 22.0 23.0 24.0 25.0 26.0 27.0 28.0 29.0 30.0 31.0 32.0 33.0 34.0 35.0 36.0 37.0 38.0 39.0 40.0 41.0 42.0 43.0 44.0 45.0 YSI, Incorporated Chlorinity: 0 Salinity: 0 14.62 14.22 13.83 13.46 13.11 12.77 12.45 12.14 11.84 11.56 11.29 11.03 10.78 10.54 10.31 10.08 9.87 9.67 9.47 9.
Oxygen Solubility YSI, Incorporated Appendix C Model 52 42
APPENDIX D CALIBRATION TABLES Calibration values for various atmospheric pressures and altitudes. inches Hg 30.23 29.92 29.61 29.33 29.02 28.74 28.43 28.11 27.83 27.52 27.24 26.93 26.61 26.34 26.02 25.75 25.43 25.12 24.84 24.53 24.25 23.94 23.62 23.35 23.03 22.76 22.44 22.13 21.85 21.54 21.26 20.94 20.63 20.35 20.04 19.
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