Generally, the higher the heat flux into a string, the lower its resonance frequency. During a frequency measurement, the readout laser will provide a constant heat input to the resonator. However, heat will also be passed on from the resonator to the silicon frame of the chip. Thus, each measurement is characterized by a certain relaxation time, in which thermal equilibrium is established. Thermal relaxation effects are more pronounced for fibers that cannot conduct heat fast, e.g. strings that are long and/or narrow.