Tips for Reliable and Accurate Measurements using the LAQUA TB220 Turbidity Meter

To get the most out of your TB220 Turbidity Meter, here are some practical tips for its usage:

CALIBRATION

1. Delete old calibration data on the meter and perform new calibration each time using the standards provided in the kit.

This ensures that the previous calibration does not affect measurement results. 

2. Check and ensure that the vials are clean and free of any smudges. 

3. Use the standards and glass vials provided by HORIBA in the TB220 meter kit. 

The TB220 meter was designed to be used in conjunction with HORIBA’s turbidity standards and glass vials, and we cannot guarantee the same level of performance if other standards or vials are used.

4. Gently invert the calibration solution vials 2-3 times before using

Doing so minimises introducing air bubbles into the solution, which can otherwise impact measurement / calibration.

5. Place the meter on a flat surface, avoid moving or vibrating it while calibration is in progress

• Tilts in the meter will distort the optical path, affecting measurement accuracy.
• Vibrations will also increase the amount of light being scattered and result in inaccurate turbidity readings. 

6. Ensure that arrow markers on the vial and meter are aligned, for reliable, consistent and repeatable results. 

7. After placing calibration solution vials into the meter, let them rest for 30 seconds to 1 minute before commencing calibration.
This is to allow the turbidity to stabilise and stop fluctuating, for more accurate result. 

For turbidity readings in the low-turbidity range (e.g. < 1 NTU), it is recommended to let the vials rest for at least 3 minutes as the effects of air bubbles and sample fluctuations are greater, which might lead to inconsistent readings.

8. To verify calibration results, perform a readback / check with the calibration standards.
Successful and good calibration allows you to obtain the values stated on the calibration standards (within acceptable range).

DURING CALIBRATION

DONE will be displayed if the calibration values are within this range:

• 0.02 NTU: ± 0.3 NTU 
• 20, 100, 800 NTU: ± 30% NTU

AFTER CALIBRATION

Perform a measurement in MEAS mode using any of the calibration standard solutions (0.02, 20, 100, 800 NTU) to verify calibration accuracy. 
If measurement is within the range stated below, the calibration is successful.

• 0.02 NTU: ± 0.02 NTU
• 20, 100, 800 NTU: ± 2% NTU

9. Dispose of calibration solutions once expired and replace them.

• Shelf-life of HORIBA’s SDVB standards is 1 year.
• SDVB standards are relatively stable, but are still susceptible to change and degradation over time even if sealed. 
• If the readings drift or fall out of the acceptable tolerance range, it is an indicator that the standard solution is likely due for replacement.

MEASUREMENT

1. Use clean sample vials for measurements.

2. If sample vial interior is dirty, wash with ethanol and allow it to dry thoroughly.

Do not wipe the interior surface to avoid introducing scratches on the internal surface of the vial. 
Ethanol can be used to rinse the glass vial interior to remove organic dirt, without causing damage to the vial. Allow the vial to dry thoroughly before using.

3. Take sample measurements promptly after sample collection.

Changes in sample conditions (e.g. temperature, humidity) can affect turbidity readings. 

4. If ambient conditions at measurement site differ slightly from calibration site, allow the meter to acclimate to new conditions before taking any measurements.

If ambient conditions at measurement site differ greatly from calibration site, recalibration at measurement site is recommended, before any measurements. 

5. If sample is expected to have low turbidity (e.g. < 1 NTU), allow sample vial to rest for at least 3 minutes before taking measurements. 

Turbidity readings in the low-turbidity range are more susceptible to interference (e.g. air bubbles, sample fluctuations). More time is required to allow the sample turbidity to stabilise, otherwise measurements might be inconsistent. 

MAINTENANCE AND STORAGE

LAQUA TB220 Turbidity Meter

Maintenance

• If dirty, wipe with dry cloth or cloth slightly dampened with alcohol.
• Do not use strong acid/alkali solutions.
• Do not use abrasives like polishing powder.
• Do not let dust or moisture enter the vial mounting section of the meter. 

Storage

• Store in an environment where the temperature is -5°C to 50°C, relative humidity is 80% or less, without dew condensation.
• Avoid storing the meter in the following locations:
  • Exposed to a lot of dust and dirt, direct sunlight, heating and/or cooling appliances, corrosive gases 
  • Places that are subjected to strong vibrations and direct wind

0.02, 20, 100 & 800 NTU standards

Storage

• Store in ambient conditions (5°C to 35°C).
• Do not freeze standard solutions.