Chemical Laboratory Section

Instruments Name

pH Meter

TDS Cum Conductivity Meter

Analytical Balance

UV-Vis Spectrophotometer

Turbidity Meter

pH Meter

Model no- Labtronics LT-150                                                 

Lab Id no –PL/DPHM/01

Switch on the instrument & allow to warm for 15 minutes at room temperature(22°C-25°C)
│
▼
Calibrate by buffer solution of pH 4.0, 7.0 & 9.0
│
▼
Calibration ok & ready to measure sample’s pH
│
▼
After 3-point calibration result display of pH of sample
│
▼
Record the pH value of the sample

Precautions:

• Clean the electrode with clean & dry tissue in every step before dipping in one buffer to another buffer to avoid cross contamination.
• Always take 3 readings to get the accuracy of result.
• Repeat the calibration process or inform the technical manager if the pH of the buffer solution is not within 0.1 pH units of the expected value.
• Repeat the calibration process or inform the technical manager if variation exceed the  ±5%

TDS Cum Conductivity Meter

Model no- Labtronics LT-51                                                 

Lab Id no -PL/DCM/01

Switch on the instrument & allow to warm for 15 minutes at room temperature(22°C-25°C)
│
▼
Adjust the cell constant to 1.0 ± 0.05
│
▼
Calibrate by standard conductivity solution
│
▼
Adjust the conductivity value to temperature(22°C-25°C) λ=1.41 ms/cm
│
▼
Calibration OK. Wash with distilled water & wipe with tissue paper.Record the displayed conductivity result of test sample

Precautions:

• Clean the electrode with clean & dry tissue before dipping from conductivity solution to sample to avoid cross contamination.
• Always take 3 readings to get the accuracy of result.
• Take the reading when the values are in stable condition.
• Repeat the calibration process or inform the technical manager if variation exceed the  ±5%

(3) Analytical Balance

Model no- Wenser -4D- 220                                                  

Lab Id no -PL/DB/01

Switch on the instrument & allow to warm for 15 minutes at room temperature(22°C-25°C)
│
▼
Calibrate the balance by standard weight box.
│
▼
Tare & check the standard weight.
│
▼
Now the required weight of sample can be taken after calibration.

Precautions:

• Always clean the balance pan before or after use.
• Close the door properly to prevent passing of air.
• Use calibrated weight box & always clean these by tissue before start calibration.
• Take the reading when the values are in stable condition.
• Use clean & dry glasswares before weighing to avoid errors in result.
• Repeat the calibration process or inform the technical manager if variation exceed the  ±5%

(4) UV-VIS Spectrophotometer

Model no- Labtronics                                                                         

Lab Id no –PL/SPM/01

Switch on the instrument & allow to warm for 20 minutes at room temperature(22°C-25°C)
│
▼
Select the absorption & set the wavelength needed
│
▼
Set the instrument to 0.000 with the solvent used
│
▼
Measure the absorbance (OD) of the developed colour of the test solution.
│
▼
Record the absorbance (OD) value & utilize in calculation.

Precautions:

• Do not keep open the sample compartment lid for long time.
• Use clean cuvette.Before placing it into the sample compartment clean the outside with tissue.
• Take the reading when the values are in stable condition.
• Avoid direct contact of light.
• Repeat the calibration process or inform the technical manager if variation exceed the  ±5%

(5) Turbidity Meter

Model no- Labtronics                                                                         

Lab Id no-PL/DTM/01

Switch on the instrument & allow to warm for 20 minutes at room temperature(22°C-25°C)
│
▼
Set the instrument to 0.000 with the distilled water
│
▼
Calibrate with standard turbidity Solution.(10 NTU,50 NTU,100 NTU)
│
▼
After the calibration measure the turbidity of the test sample.

Precautions:

• Do not keep open the sample compartment lid for long time.
• Before placing the sample bottle into the sample compartment clean the outside with tissue.
• Always use fresh intermediated turbidity solution & dilute in proper way.
• Take the reading when the values are in stable condition.
• Avoid direct contact of light.
• Repeat the calibration process or inform the technical manager if variation exceed the  ±5%