Hi Andy,
years ago there was a great paper by Julie Auger et al called: "Best Practices for Core Facilities: Handling External Customers" It was really a very good analysis of what to do with the surplus. With that in mind, and considering that our industrial customers pay X% more than our external academic customers, we transfer that x% to another account (unrelated to the cores).
Let me know if you would like to talk about this off line.
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Marimar Lopez
Director Research Cores
RENSSELAER POLYTECHNIC INST
Troy NY
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