Instrument Calibration Protocol Surface area Analyzer
| INSTRUMENT | Surface area Analyzer |
| Refer SOP No. | |
| Model No. | |
| Instrument Code No. | |
| Make | |
| Frequency | |
| Date of Calibration | |
| Next Due Date |
| Sr. No. | W.S Field | W.S. Value | Comments |
| 1 | Surface Area Analyser ID No. | ||
| 2 | Balance ID No. | ||
| 3 | Others (If any) |
| Name of Instrument | Calibration Due Date |
| Surface Area Analyzer | |
| Balance | |
| Others (If any) |
Details of Sample used
| Sr.No. | Standard Name | Batch No. /Lot No. |
| 1. | Controlled pore Glass |
1. Experiment Condition:
a) Temperature of degassing: °c
b) Time of degassing : min
c) Degassing gas:
d) Adsorbate gas :
e) Diluent gas:
f) Cooler bath:
2. Stabilization:
Kept the gas valve in BYPASS position. Stared gas supply of ________ % (30 % N2 +95 %) Pressure of the gas Pressure of the gas kept at ______ kg/cm² (1 kg/cm²). Regulated the flow to around_______ cc/min (100 cc/min) by means of adjacent flow valve. After _______ Min (20 minutes), switched on the main unit. The instrument takes 10-15 to get stabilized. After the instrument is switched ON, the LCD will display the instruction Press BAL is pressed to adjust balance. Used balance control knob on the front panel to bring BAL to _____ mv (0.00Mv)
3. Procedure for Single Point Calibration:
Single point calibration shall be performed with mixture gas 30% N₂ -70 %He.
Standard Preparation:
Weight of empty standard tube (a): g
Weight of empty standard tube + Standard (b): g
Weight of standard (b-a): g
Weighed _______ g of standard in the sample tube and regenerated it at _________° c (300 °c)
Temperature for _______min (120 min) for removing moisture and other gases.
Input all the parameters requested such as Sample name, room temperature, % Of N₂, Empty sample tube weight, Sample + tube weight before regeneration, regeneration conditions etc. After proper authentication, save it. Software will check the connectivity to the instrument. If it is ok then it will proceed for BALANCE checking and instruction screen. Follow the instructions such as start the proper gas mixture, weight the sample, regenerate O ring and wait for instrument stabilization. Click on START button to check the BALANCE of the instrument. If it is not zero then adjust it by balance control knob on the front panel. After confirming that it gives stable zero reading, press ‘STOP’ button. Press ‘CONTINUE WITH EXPERIMENT’ button to proceed for analysis. Now the graphical screen is displayed. Follow the instruction given at the bottom line. When it is asked to click on ‘PROCEED’ button, press Enter key to avoid delay.
a) Now the instruction is ‘Connect Sample Tube to Sample and Change the Valve to Sample position’.
So remove the stoppers from the sample tube, which have been taken out from Regeneration System
and connect the same to Sample port with the help of ‘O’ Rings and connecting Nuts.
b) After connection of tube, change the valve to Sample position. Click on PROCEED. The display will show instruction, ‘Dip the tube in liquid nitrogen’. Now take liquid nitrogen from cryogenic container to small dewar flask provided. Dip the Sample tube in liquid nitrogen and put black supporting boxes provided to maintain the level of dewar flask. The display will now show ‘Adsorption is about to start.’
c) When actual adsorption signal is reached to sensor, it will plot the graph for Adsorption. When the graph comes to base line, it shows the instructions that ‘Adsorption is over’. Next instruction displayed is ‘Remove the dewar flasks and dip the sample tube in water’. Follow the instruction and it will start Desorption process. The display will show ‘Desorption is about to start’. Wait till the ‘Desorption is completed’ instruction is displayed on screen.
d) Now it shows the instruction as ‘Inject appropriate quantity of Nitrogen’ Injected______(ml) of _______(30 %) N₂ gas The nitrogen gas should be taken in Gas Tight Hamilton Syringe provided along with the instrument. The quantity of N₂ gas should be such that the Desorption peak and Injection peak should be nearly same. The peak level (mV value) of every peak is displayed on top of each graph. After injection, the display will show ‘Calibration is about to start’. Wait till the calibration is completed. For wrong injections or if the peak value does not match, facility of Reinjection is provided.
e) This completes the actual Single point analysis. The software instructs to ‘Change the valve to Bypass, remove the tube and click on proceed’.
f) Remove the sample tube. Wipe the sample tube thoroughly with tissue paper and weigh it to get dry weight.
Weight of tube + Standard (W) :
g) Enter the dry weight and injected N₂ volume in the last screen. Click on Calculate button which leads to calculation and displays the result. Enter the authentication password and save the data.
h) The final report can be viewed from Report -> Surface area analysis. The printout of the same is possible by print option.
Observation
| Single Point (m2/gm) | Acceptance criteria: |
| 10.05 to 11.41 m²/gm (10.73 ±0.68 m²/gm) |
Results: Complies / Does not complies
Done By: Checked By:
4. Procedure for Multi Point Calibration:
Multi point calibration shall be performed with 5 %, 8 %, 10 %, 12 %, 15 %, & 30 % N₂+ He gas mixture.
Note: Minimum 3 points or maximum 10 points can be done.
Standard Preparation:
Weight of empty standard tube (a) : g
Weight of empty standard tube + Standard (b) : g
Weight of standard (b-a) : g
Weighed _______ gm of standard in the sample tube and regenerated it at _________° c (300 °c)
Temperature for _______min (120 min) for removing moisture and other gases.
Select the multipoint option. Enter no. of points for multipoint Calibration. Minimum 3 points should be entered. Maximum 10 points can be entered Input all the parameters requested. After proper authentication, save it. After saving, it displays a window where reference numbers for no. of points are displayed.
a) Click on which displays another small window where actual % N₂ is to be entered. Click on OK button. It will check the connectivity of the instrument with computer. If it is OK then next screen for instruction and BALANCE is displayed. Follow the instruction and click on START button to check the balance of the instrument. If it is not zero then adjust it by balance control knob on the front panel of the instrument. After confirming that it gives stable zero reading, press ‘STOP’ button. Press ‘CONTINUE WITH EXPERIMENT’ button to proceed for analysis. Now the graphical screen is displayed. Follow the instruction given at the bottom line.
b) Now the instruction is ‘Connect Sample Tube to Sample and Change the Valve to Sample position’. So remove the stoppers from the sample tube, which have been taken out from Regeneration System and connect the same to Sample port with the help of O Rings and connecting Nuts. After connection of tube, change the valve to Sample position. Click on PROCEED.
c) The display will show instruction, ‘Dip the tube in liquid nitrogen’. Now take liquid nitrogen from cryogenic container to small dewar flask provided. Dip the Sample tube in liquid nitrogen and put black supporting boxes provided to maintain the level of flask. The display will now show ‘Adsorption is about to start.
d) When actual adsorption signal is reached to sensor, it will plot the graph for Adsorption. When the graph comes to base line, it shows the instructions that ‘Adsorption is over’. Next instruction Displayed is ‘Remove the dewar flask and dip the sample tube in water’. Follow the instruction and it will start Desorption process. The display will show ‘Desorption is about to start’. Wait till the ‘Desorption is completed’ instruction is displayed on screen.
e) Now it shows the instruction as ‘Inject appropriate quantity nitrogen’ Injected____(ml) 5 % N₂ ,
____8 % N₂, ____10 % N₂ , ____12 % N₂ , ____15 % N₂ , ____30 % N₂ gas ,The nitrogen gas should be taken in Gas Tight Hamilton Syringe provided along with the instrument. It quantity of N₂gas should be such that the Desorption peak and Injection peak should be nearly same. The peak level (mV value) of every peak is displayed on top of each graph. After injection, the display will show ‘Calibration is about to start’. Wait till the calibration is completed. For wrong injections, facility of Reinjection is provided.
f) This completes the first point for multipoint analysis. DO NOT REMOVE THE SAMPLE FROM THE SAMPLE PORT. Now the instructions asks’ ‘Remove the water bath, Wipe the tube and click on Proceed.
g) After pressing Proceed button, the software will ask for the injected N₂ volume. Enter the same and save the report after authentication.
h) Click on which displays another small window where actual % N₂ is to be entered. Click on OK button. It will check the connectivity of the instrument with computer. If it is OK then next screen for instruction and BALANCE is displayed. Now select the second gas mixture cylinder and wait for stabilization. The instrument needs 15 minutes to flush the whole system with the new gas mixture. Click on START button to check the balance of the instrument. If it is not zero then adjust it by balance control knob on the front panel of the instrument. After confirming that it gives stable zero reading, press ‘STOP’ button. Press ‘CONTINUE WITH EXPERIMENT’ button to proceed for analysis. Now the graphical screen is displayed. Follow the instruction given at the bottom line.
i) Now follow step no. c to f for adsorption, desorption and calibration. All the steps are same till last point is performed.
j) After last point is completed, the instruction is displayed at the last screen is ‘Change the valve to BYPASS, remove the tube and enter the dry weight of the sample and Injected N₂ volume’.
Weight of tube + Standard (W) :
k) Now authenticate and save the data.
l) Click on Transaction -> Review option. The points analyzed are showed. Now click on SHOW icon to view the Multipoint result with BET plot. If the plot deviates and the Correlation coefficient is not acceptable then skip the point which is deviating and again click on SHOW icon.
m) Finally the approved report is saved with authentication password. The final report can be viewed from Report -> Surface area analysis option.
Observation Table:
| Observation | Acceptance Criteria | |
| Multi Point (m²/gm.) | 10.31 to 11.67 m²/gm. (10.99 ± 0.68 m²/gm.) | |
| Correlation Coefficient(R) | Correlation coefficient R : NLT 0.9975 | |
| Regression constant(R²) | Regression constant R² : NLT 0.995 |
Conclusion: Calibration found satisfactory/ not satisfactory.
Calibrated By (Sign/ Date)
Checked By (Sign/ Date)