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| I took batch 12 out of the oven and put them in a bag and placed the bag inside the clean room in the first large stainless steel container.
I also looked at the small gauge that we felt like needed to be baked and I can confirm that without further cleaning around the inside of the gauge it should not be connected to the main vacuum. I have attached a photo of the inside of the gauge. |
Following the problem with contamination particles observed in the the Leybold thermovac TTR 91, we have taken the following step to clean the gauge:
- Wipe with IPA-wetted Vectra Alpha: Cover the tip of a ziptide with Vectra Alpha wipe corner that has been wetted with IPA, push the wipe around and remove visible particulates
- Fill the gauge flange with IPA: (following Jon's recommendation to use Lesker's procedure for cleaning their Pirani gauge), flip the gauge up such that the CF flange points upward, fill the flange with IPA all the way up. Use the tip of a SSTL tweezer to agitate the IPA. Let it sits for 20 minutes, agitate every 5 minutes. After 20 minutes, pour the IPA out then spray with dry pure nitrogen
- Passive drying : Let the gauge sit inside the flowbench for 3 hours (3:30 pm to 6:30 pm)to ensure all IPA has evaporated
- Baking : Leave the gauge in oven at 50 degree C for 48 hours (maximum allowed temperature is 65 deg C, we use 50 deg C to ensure we are well below this limit). Baking started at 7pm, should finish on Sunday 7pm and ready for assembling to vacuum chamber on Monday morning
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