Eutech Instruments CYBERSCAN DO 100 User Manual

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Instruction Manual

DO 100

Hand-held Dissolved Oxygen Meter

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68X235201 rev 4 01/04

Preface

This manual serves to explain the use of the DO 100 hand-held meter. It functions as a step by step guide to help you to operate the meter and as a handy reference guide. It is written to cover as many anticipated applications of the DO 100 meter as possible. If there are doubts in the use of this meter, please do not hesitate to contact the nearest Eutech Instruments/Oakton Instruments Authorised Distributor.

Eutech Instruments/ Oakton Instruments cannot accept any responsibility for damage or malfunction to the meter caused by improper use of the instrument.

The information presented in this manual is subjected to change without notice as improvements are made, and does not represent a commitment on the part of Eutech Instruments Pte Ltd/ Oakton Instruments.

TABLE OF CONTENTS

1 INTRODUCTION 1 2 DISPLAY AND KEYPAD FUNCTIONS 2

2.1 Display 2

2.2 Keypad 3

3 PREPARATION 5

3.1 Inserting the Batteries 5

3.2 Connecting the Probe 6

3.3 Connecting the AC Adapter 7

4 CALIBRATION 8

4.1 Temperature Calibration 9

4.2 DO Calibration in Air (with ATC) –% Saturation Mode 11

4.3 DO Calibration in mg/L Mode 13

5 MEASUREMENT 14

5.1 Taking Measurement 14

6 HOLD FUNCTION 15 7 MEMORY FUNCTION 16

7.1 Data Input 16

7.2 Memory Recall 18

8 SET FUNCTION 20

8.1 SET Function in % Saturation Measurement Mode 21

8.2 SET Function in mg/L or ppm Measurement Mode 31

9 DISSOLVED OXYGEN PROBE 38

9.1 Dissolved Oxygen Princi ple 38

9.2 Probe Care 39

9.3 Membrane Housing Replacement 40

9.4 Electrolyte Solution 43

9.5 DO Probe Troubleshooting Table 44

10 TROUBLESHOOTING 46 11 ERROR MESSAGES 47 12 ADDITIONAL INFORMATION 48

12.1 Dissolved Oxygen 48

13 SPECIFICATIONS 51 14 ACCESSORIES 52 15 WARRANTY 54 16 RETURN OF ITEMS 54

Instruction Manual DO 100

1 INTRODUCTION

Thank you for selecting the DO 100 portable meter. The DO 100 portable meter is a microprocessor-based instrument that is designed to be practical and user-friendly. It is capable of measuring Dissolved Oxygen (DO) in mg/L or ppm units, % saturation and temperature. This meter has many user-friendly features – all of which are completely accessible through the water-resistant membrane keypad.

Your meter includes a dissolved oxygen / temperature probe with a submersible cable, spare membrane cap; a bottle of replacement electrolyte solution, (4) AAA batteries, and instruction manual. Please read this manual thoroughly before operating your meter.

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Instruction Manual DO 100

2 DISPLAY AND KEYPAD FUNCTIONS

2.1 Display

The LCD has a primary and secondary display.

• The primary display shows the measured DO value either in mg/L, ppm or %, depending on units of measurement selected.

• The secondary display shows the temperature in °C.

The display also shows error messages, keypad functions and program functions. See Figure 1.

Figure 1: Full LCD Screen

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Instruction Manual DO 100

2.2 Keypad

The large membrane keypad makes the instrument easy to use. Each button, when pressed, has a corresponding graphic indicator on the LCD. See Figure 2. Some buttons have several functions depending on its mode of operation.

Key Function

ON/OFF Powers on and shuts off the meter. When you switch on the meter, the meter

HOLD 1. Freezes the measured reading. To activate, press HOLD while in

MODE 1. Selects the measurement parameter. Press MODE to toggle between %

CAL/MEAS 1. Toggles between Calibration and Measurement mode.

ENTER 1. Press to confirm your calibration values in Calibration mode.

MI & MR

/ 

SET Takes you into the SETUP mode.

starts up in the mode that you last switched off from. For example, if you shut the meter off in mg/L measurement mode, the meter will be in mg/L measurement mode when you switch the meter on.

measurement mode. To release, press HOLD again.

2. In its SETUP menu, this key takes you through the main menu.

Saturation and mg/L or ppm mode.

2. While in the CAL mode under mg/L or ppm measurement status, this key will toggle between mg/L (ppm) calibration and temperature calibration (refer to Section 4.1 on page 9 to 10.)

If you were in Measurement mode, press CAL/MEAS to enter Calibration mode. To confirm calibration, press ENTER key.

To abort calibration, press CAL/MEAS key again to go back to measurement mode.

2. While in SETUP, pressing CAL/MEAS takes you out directly into the measurement mode.

2. While in SETUP, pressing ENTER key takes you through the various menu AND through each sub-menu.

In measurement mode:

Press MI / to store values in mg/L or % Saturation values with its corresponding temperature values in the memory. Up to 16 sets of values can be stored.

Press MR/ to retrieve data from memory in LIFO method.

In Calibration mode:

Scrolls up and down values with each key press, or helps make selection.

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Instruction Manual DO 100

Figure 2: Keypad

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Instruction Manual DO 100

3 PREPARATION

3.1 Inserting the Batteries

The DO 100 is packaged with 4 “AAA” alkaline batteries required for operation. To insert the batteries into the meter, follow the procedure outlined below.

1. To open the battery compartment, press down the catch of the battery cover. See Figure 3a below.

2. Note the polarity and insert the batteries into the battery compartment correctly (Figure 3b).

3. Replace the battery cover into its original position, ensuring the catch is lock into its position.

Your hand-held meter is now ready for operation.

Figure 3a: Back panel of meter

showing battery compartment

LR03 'AAA' (AM4)

MADE IN S'PORE

Figure 3b: Battery position

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Instruction Manual DO 100

3.2 Connecting the Probe

The DO 100 uses a special notched 6-pin connector to attach the probe to the meter.

NOTE: Do not substitute other probes or electrodes. For replacement probe, see

the Section 14 “Accessories” on page 52.

NOTE: Keep connector dry and clean. Do not touch connector with soiled hands.

To connect the Dissolved Oxygen probe:

1. Line up the notch and 6 pins on the meter with the holes in the 6 pin connector. Push down and screw the metal sleeve to lock the probe connector into place. See Figure 4.

2. To remove probe, unscrew the metal sleeve and slide up the probe connector. While holding onto metal sleeve, pull probe away from the meter.

CAUTION: Do not pull on the probe cord or the probe wires might disconnect.

Figure 4 - Probe Connector

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Instruction Manual DO 100

3.3 Connecting the AC Adapter

The AC adapter is not included with your meter; see the Section 14 “Accessories” on page 52. Ensure that the input mains voltage (110 or 220 V at 200 mA) matches your adapter requirements.

1. Insert the AC jack as shown in Figure 5 below.

2. Switch off the meter before plugging the adapter into the power source. This safety precaution protects the software in your meter.

3. Press the ON/OFF button to switch meter on.

Figure 5 - Using optional AC adapter

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Instruction Manual DO 100

4 CALIBRATION

The amount of oxygen dissolved in water will depend on its temperature, atmospheric pressure and its salinity. While the pressure and salinity values are manually entered into the instrument, the temperature is being measured by the probe. It is therefore very important that the temperature is calibrated if necessary prior to the DO calibration.

The measurements of % Saturation of DO will linearly affect the measurement for DO in mg/L. Hence calibration in % Saturation of DO should be carried out first. This is described in the following section.

Before calibrating, press MODE key to select the correct measurement mode. There are 2 measurement modes for DO: mg/L or ppm, and % Saturation.

NOTE: All new calibrations will automatically over-ride existing calibration values.

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Instruction Manual DO 100

4.1 Temperature Calibration

DO in mg/L is dependent on temperature, so it is first necessary to calibrate or verify the temperature reading. Temperature calibration is accessible from the mg/L or ppm measurement mode. This is illustrated in the flow diagram in Figure 7.

The temperature sensor is part of the DO probe and the “ATC” annunciator will light up on the LCD screen once the probe is connected correctly to the meter.

1. Dip the DO probe into a solution with known temperature. Allow sufficient time for the temperature to stabilise.

NOTE: Use an accurate temperature meter or bath to determine

the solution’s temperature.

2. Ensure that the meter is in measurement mode. Press MODE key if necessary to select mg/L mode.

3. Press CAL key to go into calibration mode of mg/L. The primary display shows the measured DO in mg/L and the secondary display shows the temperature.

4. Press MODE key to go into temperature offset adjustment mode. The primary and secondary displays will show the temperature values. See Figure 6.

5. Press MI/ or MR/ key to set the correct temperature value.

NOTE: The meter allows a limit of ± 10 °C variation between the

original and the adjusted value.

6. Press ENTER key to confirm the adjusted temperature. The temperature probe is now calibrated.

NOTE: To exit from Temperature Calibration mode without

confirming calibration, press CAL/MEAS key.

NOTE: Since temperature readings affect the accuracy of the

mg/L measurements, it is strongly recommended to carry out a mg/L calibration after a temperature calibration is done.

Figure 6: Temperature

Calibration

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Instruction Manual DO 100

Figure 7: Flow Diagram for Temperature and mg/L (ppm) Calibration

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Instruction Manual DO 100

4.2 DO Calibration in Air (with ATC) –% Saturation Mode

You can calibrate this meter quickly and easily in air. The exact calibration value depends on barometric pressure. The meter is set to a factory default of 760 mm Hg, which results in a calibration value of 100% saturation in air.

NOTE: If the barometric pressure setting has been changed from 760 mm Hg, the calibration value in air will automatically adjust to a value other than 100%. The adjusted value will be correct for the new barometric pressure setting. See Section 8.23 for barometric pressure setting.

To calibrate 100% Saturation:

1. Press MODE key to select % Saturation mode.

2. Rinse the probe well with deionised rinse water. For best accuracy, wipe the end of the probe dry. Do not touch the membrane.

3. Hold the probe in the air gently with the sensor facing down and press CAL key to calibrate the meter. The LCD will show a “CAL” mode. The primary display will show the current value of measurement and the secondary display will show “100.0” to which the meter is going to be calibrated. Wait for the reading to stabilise.

4. Press ENTER key to confirm the calibration. The meter automatically calibrates to 100% air saturation and returns to the measurement mode.

NOTE: To exit from DO Calibration mode without

confirming calibration, DO NOT press ENTER. Press CAL/MEAS instead.

Figure 8: Calibration for 100%

Saturation

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Instruction Manual DO 100

To calibrate 0% Saturation:

READY

MEAS

%

SET

SETUP

°C ATC

MEM

OFF

1. Power on the unit and immerse the DO probe in 0% solution. Ensure that the tip of the probe is

Figure 9: Calibration for 0.0%

Saturation

ENTER

SETUP

completely immersed. Stir gently to create a homogenous solution. Wait for the reading to stabilise. It should be less than 10%.

2. Press SET key once to go to SETUP mode. The SETUP indicator will appear above the primary display.

3. Press ENTER key once. The “OFS- P2.0” screen should appear.

4. Press ENTER key once to enter zero-point

SETUP

READY

ENTER

%

calibration mode. Wait for the reading to stabilise. If the READY indicator feature is enabled, it will appear when the reading is stable (see Ready indicator setup in section

8.1.7.).

5. Press ENTER key once. The meter

SETUP

ENTER

automatically calibrates to 0.0% saturation. The next screen should show “bAr- P2.2”.

6. Press CAL/MEAS key once to exit out of SETUP mode. The meter is now in measurement mode and should display 0.0% value.

CAL

MEAS

NOTE: You can offset your % DO Calibration; see page 24 for directions.

READY

MEAS

%

°C ATC

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Instruction Manual DO 100

4.3 DO Calibration in mg/L Mode

As mentioned in the beginning of this section, the amount of oxygen dissolved in a liquid will depend on its temperature, pressure and salinity. It is therefore very important to set these parameters correctly before attempting to do a calibration.

Temperature is measured by the meter automatically. Therefore it is important to do a Temperature Calibration (as described in Section 4.1) before attempting DO calibration.

Pressure and salinity values are keyed in manually as described in Sections 8.2.2 and 8.2.3.

1. From the measurement mode, press MODE key to select mg/L.

2. Rinse the probe well with deionised rinse water. For best accuracy, wipe the end of the probe dry. Do not touch the membrane.

3. Dip the probe into a solution where DO value is known.

4. Wait until the reading stabilises. Press CAL key.

5. Adjust to the required value by pressing MI/ or MR/ key.

6. Press ENTER to confirm the calibration. See Figure

10.

NOTE: To exit from DO Calibration mode without

confirming calibration, press CAL/MEAS key.

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Figure 10: DO Calibration

Instruction Manual DO 100

5 MEASUREMENT

During measurement, care must be taken not to allow the membrane of the DO probe touch any surface. It is always advisable to insert the probe guard (refer to Figure 33 and 34 o n pages 40 and 41). The probe can either be fully or partially immersed in the solution.

The READY indicator appears on the display when the readings stabilise. It will turn off if the readings start to fluctuate.

NOTE: It is important that the sample is stirred constantly to allow it to flow past the membrane for better readings.

5.1 Taking Measurement

1. Rinse the probe with deionised or distilled water before use to remove any impurities adhering to the probe body. If it is dehydrated, soak it for 30 minutes in tap water.

2. Switch on the meter. The MEAS annunciator appears on the top of the LCD. The ATC indicator appears in the lower right hand corner to indicate Automatic Temperature Compensation. See figure on right.

3. Dip the probe into the sample.

NOTE: When dipping the probe into the sample, make

sure the tip of the probe is completely immersed. Stir the sample gently to create a homogenous sample. Be sure to tap probe very gently to remove air bubbles. Air bubbles will cause errors in the reading.

4. Allow time for the reading to stabilise. Note the reading on the display. When the reading is stable, the READY annunciator appears.

5. To toggle between % Saturation and mg/L measurement mode, press the MODE key. See Figure 11.

Figure 11: Taking Measurement

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