Nickwinkle the Metro-Gnome wants you to place the Oscillating Frequency Scanners in such a way that when you stand amongst them, you are hit by five overlapping Oscillation fields. Return to him at Toshley's Station in the Blade's Edge Mountains after you have done so.
Take these scanners to the Singing Ridge. By dropping them in a pattern on the ground, you will create overlapping fields that will read the amplitude of the crystals. Stand amidst them in such a way that you're in five oscillation fields and I'll have the information that I need!
Your scanners will even work with those that others drop.
Oh, and it's likely that a rift will be formed! I have no idea what, if anything, will come out of it, but be prepared for the worst.