An infusion pump is provided for pumping fluid though an administration set at a constant flow rate. The pump includes a pumping mechanism for pumping fluid and operates at a pulse frequency, and a controller controls the pulse frequency. Additionally, the pump has one or more sensors configured for measuring at least one characteristic value relating to a status of the infusion pump. The controller is configured for causing the pumping mechanism to operate at a first pulse frequency, and the one or more sensors measure the characteristic value intermittently. When the measured characteristic value meets a threshold value, the controller causes the pumping mechanism to operate at a second pulse frequency different from the first pulse frequency.