Set Up Mini Clean Room

First of all, the IVC must be at room temperature before opening it. If the IVC is not warm enough, depending on the humidity of the lab, condensation may form on the detector, which we absolutely want to avoid. Additionally, before opening up the IVC you need to set up a protective shield around it such that when it is opened the insides of the IVC won’t get contaminated with dust or other such particles. Thus, a mini clean room is set up with a hepa filter line attached to keep clean air flowing through it. Also, nitrogen gas must be fed into the IVC so that when the IVC seal is broken air doesn’t rush in. This process is different than the others when gas is entered into the IVC because you will utilize the check valve to release excess pressure in the IVC, so be aware of this step to come.

1. Check the mixing chamber thermometer (for high temperature use) and make sure that the IVC is warm enough to open. If need be, perform a calculation to ensure that the temperature is higher than the dew point in the room. Once you have confirmed that the IVC is warm enough, you may continue.
2. Check to make sure the nitrogen gas cylinder is not empty. If it is, you’ll be letting air into the IVC.
3. Close all valves on the pumping manifold and all valves leading to the IVC.
4. Isolate scroll pump (it should already be connected to the pumping manifold set up).
5. Open the nitrogen gas supply from the tank by the door at the top of the stairs. Make sure that the green valve on the gas line that you’re using as the nitrogen gas supply source is closed.
6. Make sure a clear hose is connected from the nitrogen gas supply to the pumping manifold, but keep it isolated from the pump and IVC (green regulator valve should be closed).
7. You are going to pump on the clear hose to evacuate any gas or air because this hose will be used to deliver nitrogen exchange gas to the IVC and we want this to be clean. You will use the scroll pump to pump on the line:
   1. Make sure valve on scroll pump is closed, and turn on the scroll pump.
   2. Open the valve on the scroll pump.
   3. Slowly open the green regulator valve. After you’re finished evacuating the hose, the little pressure gauge above the regulator valve should read -30 in-Hg (though the pressure is actually lower than this!).
8. Close green regulator valve.
9. Open the nitrogen valve (green) on the gas supply line to let nitrogen gas into the clear hose (still isolated) it should be read under 5 PSI on the little pressure gauge, though the exact pressure depends on the regulator on the gas tank.
10. Close off scroll pump. Turn it off.
11. Open the three valves on top of the fridge that lead to the IVC.
12. Open the black valve that separates the green regulator from the IVC line.
13. You are now going to let nitrogen gas into the IVC. To monitor this process properly, you will need to keep an eye on the small pressure gauge attached to the transfer line.
    1. Slowly open the regulator valve. You will see the pressure start to decrease. This is because the IVC is under vacuum. We don’t want nitrogen gas to rush in, but, rather, slowly fill the IVC. Continue to open the regulator slightly until the pressure doesn’t seem to decrease anymore.
    2. Keep an eye on the pressure gauge. You should find that the pressure on the little gauge will begin to increase.
    3. When the pressure reads ∼ 1 PSI, open the check valve on top of the fridge. Put your hand in front of the check valve. There should not be any air rushing into the check valve. You might feel some nitrogen gas coming out (and hopefully not too much - this would mean there was a higher pressure than necessary within the IVC).
    4. Close the green regulator valve
    5. Shut off the nitrogen gas supply on the line and tank

1. Remove the transfer cone located to the side of the IVC, and place the screws in the fridge screws box.
2. Bring up the mini clean room around the IVC. It has a hole in the center through which the IVC is inserted. The correct orientation for the clean room is such that the metal cylinder faces the gas lines and hand crank. There are four strings with caribeners tight at the end which are attached to the platform. Connect each of these caribeners to a loop on a corner of the clean tent. This will support the clean tent.
3. Slide the large white ribbed hose for the HEPA filter around the metal cylinder. Use a flathead screwdriver to tighten it around the cylinder.
4. Plug in the grey power cord to turn on the HEPA filter.
5. You need to clean the mini clean room now. Put on a lab coat, hair net, and gloves. Get isopropanol and some wipes and clean the inner walls of the clean room. It’s probably best to clean the floor first so that you can sit comfortably in the clean room.
6. Once the mini clean room is fully surrounding the IVC and clean, and the IVC is filled with nitrogen gas, you are ready to open the IVC.