To lay down the procedure for operation and calibration of oxygen analyzer and anaerobic chamber.
1.0 Purpose:
To lay down the procedure for operation and calibration of oxygen analyzer and anaerobic chamber.
2.0 Scope:
This procedure is applies to the operation and calibration of oxygen analyzer and anaerobic chamber in microbiology lab.
3.0 Responsibility:
3.1 Person from concerned department directly involved in the activity shall be responsible for operation and calibration of oxygen analyzer and anaerobic chamber.
4.0 Definitions/Abbreviations:
Anaerobic condition: Incubate the samples without oxygen.
5.0 Procedure:
5.1 The materials (petriplates / bottles) having microorganisms which required anaerobic conditions shall be incubated in this anaerobic chamber.
5.2 Switch ON the Main switch of the anaerobic chamber. The anaerobic chamber has two sections the front big transparent acrylic plastic chamber is Main working chamber and the small transparent acrylic plastic chamber on right hand side is Transfer chamber.
5.3 Whenever the petriplates/bottles has to be incubated anaerobically place the petriplates/bottles on the white plate provided in the Transfer chamber and close the door and locked.
5.4 Put the hands in the gloves open the inner clamps of the Transfer chamber door. Transfer the material (petriplates / bottles) on to the left hand side provided racks in the Main working chamber.
5.5 The inner clamps of Transfer chamber door shall be slightly opened.
5.6 Switch on the vacuum pump by pressing the button ‘Vacuum Chamber’ on the black shroud (cover).
5.7 Open the vacuum valve ‘VAC’ which is located behind the Transfer chamber.
5.8 Give the vacuum until the pressure gauge shows approx. -18 to -20 inHg once it reaches close the valve ‘VAC’. While vacuuming the chamber gloves moves in to the Main chamber (Negative pressure).
5.9 Set the gas source to 25-50 PSI (340 kPa) .Purge the Main working chamber with any inert gas mixture (Nitrogen gas mixture or Argon gas mixture) by opening the ‘N2’ valve located left hand side of the Main working chamber until the pressure gauge shows‘0’ inHg once it reaches close the ‘N2’Valve. While purging with gas the gloves moves from inside of the chamber to outside (Positive pressure).
5.10 Repeat the same above mentioned procedure from steps 5.6 to 5.9 for 7 or 8 more times (in total 8 or 9 times) so that Main working chamber is completely free with air (oxygen).
5.11 Close the inner clamps of the Transfer chamber door.
5.12 Check the Oxygen level in the Main working chamber by rotating the right hand side knob to 0-100% of the Oxygen Analyzer, it should be 0 %.
5.13 Catalyst Heater Unit: The black small drum is a heater, which has Main switch and LCD display screen. Switch on the heater by pressing ‘. ‘main switch and the display shows current set temperature. As per requirement set the temperature it should be not more than 39 ºC set the temperature by pressing simultaneously ‘* ‘star button and ‘?’ up arrow key or
‘?’ down arrow key. After reaching the set temperature on the display screen place the palladium canister on the heater. This palladium canister is useful for removing the any residual air (oxygen) from the main working chamber. When palladium gets heated it reacts with O2 and H2 to form water vapours (moisture).
Removal of water vapour (Moisture): This water vapours (moisture) are condenses on the inner side wall of the main working chamber. This moisture are removed by using Drying Train switch. Drying Train switch is present on the top black shroud (cover) and simultaneously ON the Drying Train and Vacuum pump switch. The flow meter shows flow rate it should be above 4. If flow rate is below 4 then three clear plastic canisters having molecular sieves need to be Re-charged.
Re-charging the molecular sieves: Molecular sieves can be recharged by emptying the contents of the canister into a metal tray and baking in a hot oven for two hours at 232 ºC. Depress the white disconnects at each end of the clear plastic canister. Remove the canister from the black clamps. Open one end of the plastic canister and pour the contents into a metal pan.Place the pan in the oven. After two hours of recharging cool down to room temperature and pour it back into the canister. Replace the canister in the black clamp and re-connect the quick disconnects. Restart the vacuum pump to ensure the flow rate should be above 4.
5.14 Close the inner clamps of the Transfer chamber door.
5.15 Switch on the vacuum pump by pressing the button ‘Vacuum Chamber’ on the black shroud (cover).
5.16 Open the vacuum Valve ‘VAC’ which is located behind the Transfer chamber.
5.17 Give the vacuum until the pressure gauge shows approx. -18 to -20 inHg once it reaches close the Valve ‘VAC’.
5.18 Purge the Transfer chamber with the same inert gas used for purging of Main working chamber by opening the ‘N2’ Valve located behind the Transfer chamber until the pressure xgauge xshows ‘0’ inHg once it reaches close the ‘N2’Valve.
5.19 Repeat the same above mentioned procedure from steps 5.15 to 5.18 for 2 more times (in total 3 times) so that Transfer chamber is completely free with air (oxygen).
5.20 Whenever the Anaerobic chamber is using for analysis record the display temperature of the catalyst heater unit for 3 times in a day in the given format xxxxx.
5.21 Calibration of Oxygen analyzer:
5.21.1 Check the Oxygen level in the Main working chamber by rotate knob to 0-100% the display xscreen shows 0 %.
5.21.2 Take Oxygen analyzer from the chamber and rotate the left knob to calibrate position and place the receiver of the meter to atmospheric air AHU flow it should show 20.9 % and record the details in the given Format No.xxxxx.
5.21.3 Frequency: Once in six months ± 7days.
5.22 Temperature Mapping(Calibration) of the Anaerobic chamber:
5.22.1 Place 5 data loggers temperature probes inside of the anaerobic chamber through by removing the right side provided Cock valve setup and ensure that there is no leakage of the temperature as shown in the annexure-I. There is no need of Anaerobic condition for this temperature mapping.
5.22.2 Minimum set point: Set the temperature 30º c of the catalyst heater unit. After reaching the set temperature the data logger shall be recording the data. Record the temperature for 8hours with 30 minutes time interval.
5.22.3 Maximum set point: Set the temperature 35º c of the catalyst heater unit. After reaching the set temperature the data logger shall be recording the data. Record the temperature for 8hours with 30 minutes time interval.
5.22.4 Temperature mapping shall be done by external agency.
5.22.5 Frequency: Once in a year ± 15 days.
6.0 Related Documents: Nil
Microbiology, oxygen analyzer, anaerobic chamber
