Digital Dissolved Oxygen Meter AR8210

1. Introduction

This device is an intellectual precise measurement apparatus designed for high sensitivity and accuracy. It is stable for use across various temperatures and is compact for easy storage and portability. The meter measures dissolved oxygen values and solvent temperature. It is widely applied in industrial, electrical, agricultural, medical, food, and water quality monitoring. Please read this manual thoroughly before use to ensure correct readings and operation.

The AR8210 features a handheld design with a non-slip pen-type handle for easy operation, built-in automatic temperature compensation (ATC) for precise results, and a measuring range of 0.00-20.00 mg/L. It also includes switchable temperature units (℃ / ℉) and a backlight for convenience in dark environments. The sensor probe is replaceable with an insert-type design for quick and easy replacement.

2. Package Contents

The standard package for the AR8210 Dissolved Oxygen Meter includes:

• 1x Dissolved Oxygen Meter (Main unit)
• 1x USB Cable
• 1x Dissolved Oxygen Electrode Probe
• 10x A Type Reagent
• 10x B Type Reagent
• 3x Protection Cover
• 1x User Manual (this document)
• 1x Certificate of Calibration

Note: Due to shipping limitations, electrolyte liquid is typically not included in the package.

3. Product Overview

1. USB Port (for charging)
2. LCD Display
3. Power ON/OFF / Data Hold Button
4. Calibrate Button
5. Backlight / Reduce Button
6. Dissolved Oxygen Electrode Probe

4. Setup and Calibration

4.1 Initial Probe Preparation

The probe must be calibrated before its first use and after prolonged idling. It is recommended to calibrate before any precise measurements.

1. Ensure the probe is dry before calibration.
2. Take out the new probe reservoir. Fill it with fresh electrolyte (not included in package) up to 3/4 capacity, ensuring no air bubbles are present. If bubbles exist, gently tap the probe to dislodge them.
3. Screw the probe reservoir back onto the probe handle until the membrane touches the gold cathode. Keep the reservoir as bubble-free as possible.
4. If electrolyte overflows, clean it with a soft paper.
5. Plug the probe connector into the main unit.
6. Turn on the device and wait for at least 30 minutes before use.
7. If the value changes very little after immersing the probe in hydrogen peroxide water or saturated dissolved oxygen water, replace the probe reservoir and add fresh electrolyte.

4.2 Air Calibration

The instrument uses an air calibration method. Before calibrating, connect the probe to the main unit and turn it on for 30 minutes.

1. In normal measurement mode, press and hold the "CAL" button for 3 seconds to enter calibration mode.
2. Place the probe in the air and wait for two to three minutes until the reading stabilizes.
3. Press the "CAL" button until the LCD screen displays "PAS". The instrument will store the setting value and return to normal measurement mode.
4. If the LCD screen displays "Err", calibration has failed. This may indicate the value is outside the calibration range or the probe is damaged.

4.3 Salinity and Altitude Compensation

After successful air calibration, if the sample liquid is saline or the test location is not at sea level, perform the following compensation adjustments:

1. In normal measurement mode, long press the "SET" button to enter compensation setup mode. The LCD screen will show "TDS" and "Salinity value" flashing.
2. Use the "CAL" button to increase the salinity value (long press for faster increase) and the "SET" button to reduce the value (long press for faster decrease).
3. After setting salinity, press the "HOLD" button to save the setting and enter Altitude compensation mode (AP). The LCD screen will show "AP" and "AP value" flashing.
4. Use the "CAL" button to increase the altitude value and the "SET" button to reduce the value.
5. To switch altitude units (mmHg and KPa), press "CAL" and "SET" buttons simultaneously.
6. After setting the AP value, press the "HOLD" button to save the setup value and return to normal measurement mode.

Note: The salinity value must be measured by a salinometer. The altitude value must be measured with an altimeter. The default salinity is zero, and the default altitude is sea level (101.3-79.9Kpa or 760-600mmHg).

5. Operating Instructions

5.1 Button Functions

• Power ON/OFF / Data Hold Button (HOLD):
  • Short press to turn the unit ON.
  • After unit is ON, short press to hold the measured value.
  • Long press (more than 3 seconds) to turn the unit OFF.
• Calibrate Button (CAL):
  • Press for more than 3 seconds to enter Calibration mode.
  • In compensation mode, press to increase values (long press for faster increase).
• Backlight / Reduce Button (SET):
  • Short press to toggle backlight ON/OFF.
  • In compensation mode, press to reduce values (long press for faster decrease).

5.2 Auto Power Off Setup

To configure auto power off:

1. Before turning on the unit, press and hold the "HOLD" and "CAL" buttons simultaneously to enter auto power on/off setup mode.
2. The LCD display will show "APO ON" or "APO OFF".
3. Press the "HOLD" button to select between "APO ON" (auto power off after 5 minutes of inactivity) or "APO OFF" (no auto power off).
4. Long press the "HOLD" button to save the selection and return to normal measurement mode.

5.3 Temperature Unit Selection

To change the temperature unit:

1. Before turning on the unit, press and hold the "HOLD" and "SET" buttons simultaneously to enter temperature selection mode.
2. The LCD screen will show "℃" or "℉".
3. Press the "HOLD" button to select the desired unit.
4. Long press the "HOLD" button to save the selection and return to normal measurement mode.

6. Maintenance

6.1 Probe and Electrode Maintenance

It is highly recommended to maintain the probe and electrode every six months. Keep the probe clean and its head inside the protection cover when not in use. Periodically clean the electrode and refill the electrolyte with fresh solution.

1. Remove the probe from the instrument.
2. Unscrew the old diaphragm set from the probe head. Clean the metal electrode and old diaphragm with distilled water.
3. If the golden cathode electrode becomes dark, polish its surface using polish paper. Apply a drop of deionized water to the polish paper, then polish the golden electrode for 5-10 turns. Clean the golden cathode with deionized water, then dry it with clean paper. Ensure the surface of the golden cathode is bright again.
4. Clean the silver anode electrode. If its silver-grey color becomes dark grey, polish its surface with polish paper until it becomes bright.
5. Add electrolyte (not included) to a new diaphragm, filling it about 3/4 of the way, ensuring no air bubbles are present.
6. Screw the new diaphragm with the added electrolyte onto the electrode until tightened.

Remarks: If too much electrolyte overflows, clean it with a soft paper.

6.2 Storage of Electrode

• Short-period storage (overnight or between measurements): Keep the electrode in the instrument, then place it into clean water.
• Long-period storage: If the electrode will not be used for a long time, store it in a dry area after cleaning it with boiled distilled water and allowing it to cool down. Do not turn on the unit during cleaning. The instrument should be stored in an environment with humidity less than 85% RH and temperature not higher than 40 °C.

7. Troubleshooting

• "Err" displayed during calibration: This indicates that calibration failed. The value might be outside the calibration range, or the probe could be damaged. Inspect the probe and ensure proper electrolyte filling and cleaning.
• Unstable readings or slow response: Check the probe for cleanliness and ensure the electrolyte is fresh and free of bubbles. Recalibrate the probe if necessary.
• Battery empty indication: If the LCD shows an empty battery icon, open the battery door and plug in the USB cable to charge the instrument. A full charge takes approximately 4 hours.
• Inaccurate readings: Ensure the probe is properly calibrated. Verify that salinity and altitude compensation settings are correct for your specific testing conditions.

8. Specifications

9. Warranty and Support

9.1 Warranty Period

The warranty period for the composite electrode is one year from the date of storage. During this period, if a malfunction of the instrument or electrode is found, the factory will repair or replace it with a functional unit.

9.2 Special Announcement

The manufacturer reserves the right to change the design and user manual without prior notice to the end user.

Version: 6-82100-0116-03

For further assistance, please refer to the official user manual PDF available at: Digital Dissolved Oxygen Meter User Manual (PDF)

10. User Tips

• Regular Cleaning: Always clean the probe thoroughly with distilled water after each use to prevent residue buildup and ensure accurate readings.
• Electrolyte Freshness: Ensure the electrolyte solution in the probe reservoir is fresh and free of bubbles for optimal performance. Replace it as recommended in the maintenance section.
• Proper Storage: For long-term storage, follow the guidelines to keep the electrode dry and in a suitable environment to prolong its lifespan.
• Environmental Factors: Be mindful of salinity and altitude at your testing location and apply the appropriate compensation settings for the most accurate results.
• Battery Management: Charge the device fully before extended use. The USB charging port makes it convenient to recharge.