PHS-25CW/3CW/3BW laboratory pH meter

Instructions for use

Preface

Thank you for choosing Bante Instruments' PHS-W series laboratory pH meter. This operation manual describes the instrument's functions and features step by step. Please read carefully before use.

Open the package

The table below describes the standard configuration of the instrument at the factory. After opening the package, please carefully check that all accessories are complete. If you have any questions, please contact an authorized Bante Instrument distributor immediately.

• pH electrodes

• Temperature probe (PHS-3BW model only)

• pH standard buffer reagents (pH 4.01, 7.00, 10.01)

• DC9V power adapter

Display screen

The PHS-W series instruments are equipped with a clear backlit LCD display to show measurement values and function icons.

Icon index:

1. Electrode slope icon: After calibration. If the electrode slope or calibration results do not meet the measurement requirements, the icon will automatically turn off

2. Measurement icon: Indicates the instrument is measuring mode

3. Calibration icon: Indicates the instrument is calibrating mode

4. Temperature icon: Indicates the instrument is in temperature setting mode

5. Error alarm: indicates that the current pH standard buffer has deteriorated or the electrodes have aged

6. Automatic temperature compensation icon: indicates that the automatic temperature compensation function is enabled

Key functions

The instrument panel's membrane panel has 8 function buttons, with names and symbols describing their controls.

Connectors

The back panel of the PHS-W series instruments has three connectors; details of each connector are listed in the table below.

Install the electrode frame

The instrument is equipped with a lightweight and easy-to-use electrode bracket for placing electrodes and temperature probes. Before use, please follow the steps below to install.

The electrode base of the instrument has an irregular round hole.

2. The lower end of the electrode frame has a cylinder with a limiting plate.

3. Align the limiting plate of the electrode holder with the groove, insert it, and rotate 90 degrees to complete the installation.

Adjust the electrode frame

After installation, if the electrode holder's lever arm automatically drops when lifted, you need to appropriately adjust the fixing screws inside the bracket.

1. Remove the plastic cover on the right side of the electrode holder.

2. Use a screwdriver to tighten the internal screws moderately until the lever arm can be positioned anywhere.

3. Insert the plastic cover into the previous position and adjust completely.

Connect the pH electrode

Remove the electrodes from the packaging box and insert the electrode sensor into the jack on the left or right side of the electrode holder as shown below.

A. Insert the electrode and hook the cable into the slot

2. Insert the BNC connector of the pH electrode into the connector holder labeled ELECTRODE on the dashboard's back panel, rotate clockwise, and lock it. After connection, do not pull the electrode connection wire. Ensure connectors are always dry and clean

Connect the power adapter

To ensure the safety of the instrument, before connecting the power adapter, please make sure the instrument is turned off and that the power adapter plug is not plugged into an external power socket.

1. Plug the power adapter into the instrument panel's POWER port.

2. Plug the power adapter into the external power socket and complete the connection.

Instrument switching

● Press the ON button to turn on the instrument, displaying measurement values and mode icons on the screen.

● Press and hold the ON button for 5 seconds to turn off the instrument.

Prepare pH standard buffer

The PHS-W series instruments come with three packs of pH standard buffer reagents at the factory.

1. Take out the standard buffer reagent, cut open the seal, and pour the reagent into a volumetric flask.

2. Add distilled water to a volumetric flask and stir the solution until the reagents inside the flask are completely dissolved.

The preparation method for different bagged standard buffer reagents is the same as above. The prepared standard buffer should be sealed and stored in a glass container. If flocculent substances appear inside the bottle, do not use again.

Before use

Remove the plastic protective cover at the front end of the electrode. If the glass-sensitive film on the sensor has dried, immerse the electrode in potassium chloride solution or tap water for a few minutes. Do not use distilled or deionized water, as this will cause sensor failure.

Glass-sensitive membranes

Temperature compensation

To obtain accurate measurement results, you need to enable automatic or manual temperature compensation before calibration or measurement.

Manual temperature compensation:

1. A high-precision thermometer is used to measure the temperature value of the sample.

2. Press  ^o Press C to enter manual temperature compensation mode on the instrument.

3. Press the ▲ or ▼ key to set the current sample temperature, press ENTER to return the instrument to measurement mode, and the setting is complete.

Automatic temperature compensation:

This section is only valid for users purchasing the PHS-3BW model. If you are purchasing a meter other than this model, please proceed directly to the next chapter.

1. Remove the temperature probe from the packaging box and insert it into the round hole in the center of the electrode holder.



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3. Insert the temperature probe connector into the ATC socket on the back panel of the instrument.



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5. The "ATC" icon on the screen is displayed immediately, and the instrument enters automatic temperature compensation mode.

pH calibration

The series instruments feature point calibration functionality, and the available standard buffers include: Standard or Standard. When using or replacing a new electrode for the first time, be sure to calibrate the instrument. To ensure high measurement accuracy, it is recommended to calibrate the instrument regularly. After calibration, do not reuse standard buffer solution, as impurities remaining in the liquid will affect the instrument's final accuracy.

1. Clean the pH electrode with distilled or deionized water, press the CAL button, and the screen will show CAL7.00 (or CAL 6.86). The instrument will indicate the standard buffer needed for point 1.



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3. Immerse the electrode sensor in pH 7.00 standard buffer solution and stir slowly. Press the ENTER key to start instrument calibration.

4. After the calibration value stabilizes, the value will automatically flash 3 times, indicating that point 1 calibration is complete.



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6. The screen automatically displays CAL ----, indicating waiting for point 2 calibration.

7. Clean the electrodes with distilled or deionized water, and use filter paper to absorb water droplets from the electrode rods.

   If your sample is an acidic liquid, use pH 4.01 standard buffer to calibrate point 2; If your sample is an alkaline liquid, calibrate point 2 with a pH 10.01 (or pH 9.18) standard buffer. The instrument will automatically recognize the above calibration fluid.

8. Immerse the pH electrode in a standard buffer solution of pH 4.01 or 10.01 (pH 4.01 or 9.18) and stir slowly.

9. Press ENTER to start instrument calibration.



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11. After the calibration value stabilizes, the value will automatically flash three times, indicating that calibration at point 2 is complete. The instrument will automatically display the electrode slope value and return to measurement mode.



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After calibration, if the electrode slope shown by the instrument is below 85%, please confirm the following:

1. Have you used fresh pH standard buffer to calibrate the instrument?

2. Check whether the glass-sensitive film and reference core of the electrode sensor are covered by contaminants. If the above factors are excluded, consider replacing the pH electrode.

Exit calibration: During calibration, if you wish to exit calibration mode and not save values, pressing the pH key will immediately return the instrument to measurement mode.

pH measurement

Thoroughly clean the electrodes with distilled water and immerse them in the sample to stir slowly. After the measured values stabilize, record the values.

mV measurement

● In pH measurement mode, press the mV button, and the screen will display the measurement unit in mV.

● Thoroughly clean the electrode sensor with distilled water and immerse it in the sample to stir slowly. After the measurement stabilizes, record the value.

Cleaning and maintenance of electrode sensors

To ensure the normal use of the pH electrode, after each measurement or calibration, be sure to rinse the electrode's sensitive film and liquid junction with distilled water. If the electrodes are not used for a long time, soak the sensor in the electrode soaking solution for storage. It is prohibited to soak electrodes in pure water or distilled water. If the measured sample contains the following substances, it is recommended to clean using the following methods:

1. Salts: Soak the pH electrode in tap water for 10 to 15 minutes, then rinse with distilled water.

2. Grease substances: Clean the electrode-sensitive membrane with a small amount of detergent, then rinse the electrode with distilled water.

3. Protein residue: Prepare 0.1M hydrochloric acid solution and add 1% pepsin solution, immerse the sensor in the above solution for 10 to 15 minutes.

4. After measurement, if the reference terminal of the electrode is blocked, immerse the sensor and heat it to 60°C ^o Dilute potassium chloride solution of C for 10 minutes, then placed in room temperature potassium chloride solution to cool.

How to prepare the electrode soaking solution: Weigh 22.365g of potassium chloride reagent and dissolve it in 100mL of distilled water, add a small amount of pH 4.01 standard buffer, and stir the solution until fully dissolved.

Select the appropriate pH electrode

Due to the chemical properties of pH electrodes, when measuring different samples, you need to select different sensors. The table below shows the application fields and order numbers of various pH electrodes.

Troubleshoot

The PHS-W series instruments display fault codes. The table below lists the causes of faults and solutions for each code.

Technical specifications

Appendix: Choose NIST or USA buffer standards

The default buffer for the instrument is standard when it leaves the factory. If you need to switch to standard, please follow the steps below.

1. Press the ON button to turn on the dashboard.

2. Hold down the CAL key and unplug the power adapter from the external power socket.



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4. Plug in the power adapter again and release the CAL button.



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6. Press the ON key to complete the setup.

If you need to resume using the USA standard buffer set, repeat the steps above.

Hazardous Substance Statement

Bante Instruments Limited is committed to the reduction and eventual elimination of all hazardous substances in both the manufacturing process and finished products we supply. We have an active manufacturing and procurement program to minimize and eliminate the use of harmful heavy metals such as cadmium, lead, mercury and the like. New technologies and design parameters are also promoting these efforts and we expect to have little or no such materials in our product in the coming years. We welcome our customer suggestions on how to speed up these efforts.

Warranty

The warranty period for meter is one year from the date of shipment. Above warranty does not cover sensor and calibration solutions. Out of warrant products will be repaired on a charged basis. The warranty on your meter shall not apply to defects resulting from:

• Improper or inadequate maintenance by customer.

• Unauthorized modification or misuse.

• Operation outside of the environment specifications of the products.

For more information, please contact the nearest authorized distributor.