SOP FOR OPERATION AND CALIBRATION OF VACUUM OVEM

1. OBJECTIVE:

1. To lay down the procedure for Operation and Calibration of Vacuum Oven.

2. SCOPE: 

1. This procedure is applicable for the Operation & Calibration of Vacuum Oven at Quality Control Laboratory.

3. RESPONSIBILITY:

1. Quality Control Officer / Executive are responsible to follow procedure as per the procedure mentioned in this SOP. 

2. QC Head is responsible for implementation and compliance of the procedure as per this SOP.

4. ABBREVIATIONS

1. SOP    :    Standard Operating Procedure

2. QC    :    Quality Control

3. E.R.G.    :    Energy Regulator

5. PROCEDURE: 

1. Procedure For Operation:

1. Ensure that the chamber, the flange and the rubber gaskets from the inside of the instrument are clean.

2. Check the mains supply.

3. Place the sample inside properly.

4. Close the glass doors and tighten it with knobs. Connect rubber pipe from the vacuum pump to the nozzle provided. The pointer will move anti-clockwise towards 760mm. When the desired vacuum is obtained, close the cock and stop the vacuum pump.

5. Now set the required temperature by pressing the Red switch and rotating the screw provided on Right hand side corners of controller.

6. To check the set temperature press the Red switch, the display will show the set temperature of the oven.

7. Keep the Energy Regulator (E.R.G) in extreme anti-clockwise position to limit the initial temperature over shoot. Let the temperature stabilizes. It will be less than set temperature.

8. Turn E.R.G. knob clockwise a little, wait for sometimes, if temperature is not attained turn E.R.G knob further, wait for sometime or vice-versa. Do this trial and error method until set temperature is achieved. The temperature achieved will be within accuracy of 1ºC.

9. If there is moisture present in the chamber while heating vacuum may fail, restart the vacuum pump to set the desired vacuum.

2. Procedure For Calibration:

1. Perform the calibration at room temperature.

2. Operate the instrument as per the operation procedure of vacuum oven.

3. Set the vacuum at pressure 760-mm of Hg or adjust maximum vacuum.

4. Set the temperature for 50°C and 200°C separately.

5. Wait for some time and check the actual temperature by certified (calibrated) thermometer.

6. Acceptance criteria ±1.0°C of set temperature.

7. Check the vacuum set initially. It should be constant for at least 3 hours.

8. Acceptance criteria ± 20mm of set pressure.

9. Note down the readings in the format as per Half Yearly Calibration of Vacuum Oven (Annexure I).

10.  Frequency: Half Yearly. 

11. If the instrument is out of order, tag the instrument with label   

                  

12. Inform to the service engineer for rectification. Calibrate the instrument after rectification.