SMART SENSOR AS218 Digital pH Meter Instruction Manual

1. Introducció

The SMART SENSOR AS218 is a precision electronic device designed for measuring the pH of aqueous solutions. It determines the concentration or activity of Hydrogen ions, indicating whether a solution is acidic or basic. This meter also provides mV and temperature measurements, making it a versatile tool for various applications. It consists of a main body with an LCD display and a special measuring probe (glass electrode).

Figure 1: SMART SENSOR AS218 Digital pH Meter

2. Informació de seguretat

Please read and understand all instructions before using the device. Keep the device away from children. Do not attempt to disassemble or modify the device, as this will void the warranty and may cause damage or injury. Handle the glass electrode with care to prevent breakage.

3. Contingut del paquet

• 1 x SMART SENSOR AS218 Digital pH Meter (Battery not included)
• 1 x Estoig de plàstic
• 1 x pH composite electrode

Figure 2: pH Meter and accessories in carrying case

4. Producte acabatview

4.1. Components del dispositiu

1. Botó ON/OFF
2. Botó MODE
3. MAX/MIN HOLD button
4. Botó de selecció ° C / ° F
5. CAL/backlight button
6. Pantalla LCD
7. Electrode assembly (connected via cable)
8. Electrode liquid storage bottle (for electrode protection)

Figure 3: Close-up of the meter's display and buttons

4.2. Indicadors de la pantalla LCD

1. Indicació de bateria
2. HOLD function indicator
3. MIN Measurement indicator
4. MAX Measurement indicator
5. PH measured value
6. READ function indicator
7. Temperature Measured value

5. Especificacions

5.1. Normal Operating Conditions

• Environment temperature: 0 ~ 35°C
• Relative humidity: Not more than 80%
• Measured solution temperature: 5 ~ 60°C
• Power supply: 9V DC battery (006P)
• No significant vibration
• Absence of external magnetic field interference

6. Configuració

6.1. Instal·lació de la bateria

1. Locate the battery door at the back of the instrument.
2. Obriu el compartiment de la bateria.
3. Insert a new 9V battery (type 006P) into the compartment, ensuring correct polarity.
4. Tanqueu la porta de la bateria de manera segura.

Figure 4: Battery compartment and electrode connection

7. Calibració

Calibration is crucial for accurate measurements. Perform calibration before first use, after replacing the pH composite electrode, or if measurement accuracy is in doubt. If measuring intervals are short, monthly calibration is generally sufficient.

7.1. Important Calibration Notes

• The unit and calibration solutions must be at an ambient temperature of 25°C ± 2°C during calibration.
• Always rinse the pH electrode with distilled water before and after immersing it in buffer solutions.

7.2. Three-Point Calibration Procedure

1. Initiate Calibration Mode: Press the "MODE" key repeatedly to cycle through the three different calibration modes: (CAL 1), (CAL 2), and (CAL 3). The display will show "C4.0", "C6.86", or "C9.18" with a flashing symbol.
2. PH4.00 Buffer Solution Calibration:
   • Press "MODE" until the (CAL 1) icon is shown and flashing.
   • Esbandiu l'elèctrode de pH amb aigua destil·lada.
   • Immerse the electrode in the PH4.00 buffer solution.
   • Wait for the electrode to stabilize (the mV value should stop changing and remain constant).
   • Press the "CAL" key for more than 3 seconds. The (4.00) flashing will stop and disappear, indicating PH4.00 calibration is complete.
3. PH6.86 Buffer Solution Calibration:
   • Press "MODE" twice until the (CAL 2) icon is shown and flashing.
   • Esbandiu l'elèctrode de pH amb aigua destil·lada.
   • Immerse the electrode in the PH6.86 buffer solution.
   • Wait for the electrode to stabilize.
   • Press the "CAL" key for more than 3 seconds. The (6.86) flashing will stop and disappear, indicating PH6.86 calibration is complete.
4. PH9.18 Buffer Solution Calibration:
   • Press "MODE" three times until the (CAL 3) icon is shown and flashing.
   • Esbandiu l'elèctrode de pH amb aigua destil·lada.
   • Immerse the electrode in the PH9.18 buffer solution.
   • Wait for the electrode to stabilize.
   • Press the "CAL" key for more than 3 seconds. The (9.18) flashing will stop and disappear, indicating PH9.18 calibration is complete.

8. Instruccions de funcionament

8.1. Normal Measurement Mode (pH and Temperature)

1. Turn on the device by pressing the ON/OFF button. The factory default mode is normal measurement.
2. Esbandiu l'elèctrode de pH amb aigua destil·lada.
3. Immerse the electrode into the solution you wish to measure.
4. The LCD will display both the pH value and the environment temperature simultaneously.

Figure 5: Measuring pH in a solution

8.2. mV Measurement Mode

1. Enceneu el dispositiu.
2. Press the "MODE" key four times to enter mV measurement mode.
3. In this mode, the device can measure ion-selective, ORP (oxidation-reduction potential), and other precise mV values.
4. The LCD display will show the mV value and the ambient temperature simultaneously.

8.3. MAX/MIN Hold Function

• Press the "MAX/MIN HOLD" button during measurement to capture the maximum or minimum reading.
• Press again to cycle through MAX, MIN, and current readings.

8.4. Selecció de la unitat de temperatura (°C/°F)

• Press the "°C/°F" button to switch between Celsius and Fahrenheit temperature units.

8.5. Control de la llum de fons

• Press the "CAL/backlight" button briefly to toggle the display backlight on or off.

9. Manteniment

9.1. Cura dels elèctrodes

• Always keep the pH electrode moist. The liquid on the probe acts as a protector and should not be removed.
• After each use, rinse the electrode thoroughly with distilled water to prevent contamination.
• Store the electrode in its liquid storage bottle when not in use to maintain its condition.

9.2. Substitució de la bateria

• If the battery power indicator icon on the display becomes empty, replace the 9V battery immediately following the instructions in Section 6.1.
• For long-term storage (when the instrument will not be used for an extended period), remove the battery from the compartment to prevent leakage and potential damage to the instrument.

9.3. Neteja

• Wipe the main body of the meter with a clean, dry cloth. Do not use abrasive cleaners or immerse the main unit in water.

10. Solució De Problemes

10.1. When to Recalibrate

Recalibration is necessary under the following circumstances to ensure accurate readings:

• The solution temperature has a large difference from the temperature at which the meter was last calibrated.
• The pH electrode has been exposed to air for an extended period.
• A new pH electrode has been installed.
• After measuring highly concentrated acid solutions (e.g., pH 12 or higher).
• After measuring fluoride solutions or solutions with extreme pH values.

10.2. Problemes comuns

• Lectures inexactes: Ensure the electrode is clean, properly stored, and calibrated according to the instructions. Check for electrode damage.
• Sense pantalla/Pantalla tènue: Check battery level and replace if necessary. Ensure battery is installed with correct polarity.
• Temps de resposta lent: The electrode might be dirty or aging. Clean the electrode or consider replacement if cleaning does not improve performance.

11. Consells d'usuari

• For best accuracy, allow the meter and buffer solutions to reach room temperature before calibration.
• Always use fresh buffer solutions for calibration. Expired or contaminated buffers can lead to inaccurate results.
• When taking measurements, gently stir the solution with the electrode to ensure a homogeneous sample and stable reading.
• Avoid touching the glass bulb of the electrode, as oils from your skin can contaminate it.

12. Garantia i Suport

This product is covered by a standard manufacturer's warranty against defects in materials and workmanship. For warranty claims or technical support, please contact your retailer or the manufacturer directly. Keep your purchase receipt as proof of purchase.