That's odd; most folk go to extremes to avoid 50Hz or 60 Hz sensitivity because it's almost always a problem. Handily, if you always integrate over one tenth second, you get an integer number of full cycles of either 50Hz or 60Hz, it's all cancelled to first order.
One little wall-wart in your rack-mount will be within 1 foot of up to eight 2U boxes. I've seen a high-intensity lamp transformer ruin my data from that distance.