Dynamic nanomechanical analysis of a sample is performed by using a cantilever probe that interacts with the sample using a force applied across a wide range of frequencies that includes frequencies greater than 300 Hz. The insert can be made of flexible PVC vinyl or of a similar substance giving the user the ability to quickly install the insert into a mop bucket. Corners of the frames are miter-matched such that air spaces inside form an airloop. The absorption solution is cooled between the second membrane contactor and the first membrane contactor. Alternatively, the holdover reference generating circuit may select the input of the PLL circuit at the time of an error, and then perform holdover.