LAQUAtwin Meters - Spare Sensors and Standards

LAQUATWIN Three Step Measurement

Follow simple, good testing procedures for accurate and dependable results:

• Calibrate correctly
• Avoid mixing samples and standards
• Always keep the sensor clean

1 Calibrate

Always ensure the sensor is clean before calibrating. If not, clean thoroughly with water (don’t worry, LAQUAtwin meters are completely waterproof!). Place some standard solution on the sensor and press the calibration button. Once the smiley face appears, indicating that calibration is complete, wash off the standard solution with water and dry with a clean, soft tissue.

2 Test

LAQUAtwin meters only need a tiny amount of sample - so no beaker is necessary. Fill the sensor with the sample and when the smiley face appears, the measurement is complete.

3 Clean

Clean the sensor thoroughly with water, ready for the next test. When the sensor is nearing the end of its usable lifetime, it can be replaced;

• You don’t need to replace the meter.
• Sensors will need to be replaced after approx.

1500 measurements or when calibration cannot be completed. Sensors are sold separately and are easily removed and replaced.

LAQUATwin One meter Six Different Methods

Choose the best method according to your sample, your situation and your needs.

• Immersion: When you’re in the lab, you can test the sample in a beaker. Ensure the sensor guard sliding cap is open.
• Scoop: Use as a scoop to test water, for example from a river.
• Drops: LAQUAtwin meters can measure sample volumes as low as 0.05 mL. Place a drop of the sample onto the sensor with a pipette. Using the HORIBA sampling sheet, volumes down to 0.05 mL can be tested (except for conductivity measurements).
• Solid samples: Foods containing some moisture can be tested by placing a small piece directly onto the sensor.
• Powders: LAQUAtwin meters can also test dry powders. Simply place the powder sample onto the sensor, and drop on your defined volume of pure water.
• Paper and textiles: To test sheets of paper and textiles, cut up the sample into small pieces and place directly onto the sensor. Drop on your defined volume of pure water.

LAQUAtwin sampling sheet.

The sampling sheet allows trace volumes to be analysed. For example, you can even measure the pH of human skin by wiping with a sampling sheet soaked in pure water, and placing it on the sensor. Using the HORIBA sampling sheet, volumes down to 0.05 mL can be tested (except for conductivity measurements).

General Laboratory and Field Samples

• Plastic-body pH electrodes, either refillable or gel-filled, are ideal for field measurement. 
• The glass membrane of refillable electrodes offers an excellent response to low-conductivity water. When the refilling port is covered with the movable slider, the electrode can be used in submerged measurements for up to 30 minutes in a 1m depth of water. 
• Gel-filled pH electrode does not require refilling.
• ToupH electrodes are more impact-resistant than conventional glass-body pH electrodes due to their thick glass membrane. These electrodes are recommended for general laboratory samples.

Examples below:

• 9651-10D (for field-testing)
• 9625-10D (for general-purpose use)
• 9615S-10D Standard ToupH electrode (for general laboratory application)
• 9415-10C Standard ToupH electrode (for general laboratory application)

Precise Measurement

• High stability is required for precise measurement.
• The following electrodes have glass membranes highly sensitive to low-conductivity water and non-aqueous solvents. A movable sleeve is used at the liquid junction for easy cleaning and clog-free measurement.

• • 9481-10C Sleeve ToupH electrode (for viscous and non-aqueous samples)
  • 9681S-10D Sleeve ToupH electrode (for viscous and non-aqueous samples)
  • 6367-10D (for high accuracy pH measurement)

Smaller Volume Samples

• The volume of the sample must be enough to cover the glass membrane and liquid junction of the pH electrode during measurement.
• ToupH electrodes are constructed with a thick glass membrane that is highly resistant to impact and chemicals.
• Long pH electrodes, which come in 3 mm and 8 mm diameters, are suitable for test tubes and tall containers, while micro pH electrodes with 3 mm diameter are perfect for small tubes and trace amounts of samples. 

Examples below:

• 9618S-10D Micro ToupH electrode (for low-volume samples)
• 9418-10C Micro ToupH electrode (for low-volume samples)
• 9680S-10D Long ToupH electrode (for large containers and long tubes)
• 9480-10C Long ToupH electrode (for large containers and long test tubes)
• 6069-10C (for very slender test tubes)

Low Conductivity Samples

• pH measurement of low conductivity samples such as pure water and non-aqueous solvents can be very challenging.
• The glass membranes of the following pH electrodes produce an excellent response in the above-mentioned samples.
  • 9481-10C Sleeve ToupH electrode (for viscous and non-aqueous samples)
  • 9681S-10D Sleeve ToupH electrode (for viscous and non-aqueous samples)
  • 9630-10D (for low conductivity samples)

Solid and Semi-solid Samples

• Needle-type pH electrodes can be used to pierce and penetrate solid samples, such as meat, fruits, and food samples, during measurement.
• Flat pH electrodes and ISFET electrodes are ideal for surface pH measurement of moisture-containing solids such as nutrient agar, skin, cloth, leather, paper, meat, and leaves. 
• ISFET electrodes can also be used in food processing and other applications where glass is prohibited.
  • 6252-10D (for food samples)
  • 6261-10C (for flat surface measurement)