A tip clearance measurement system (TCMS) comprising: a probe that both directs signals toward a turbine blade and receives signals reflected by the turbine blade; circuitry comprising: a switch having a first state in which a main frequency signal having a main frequency is provided at an output of the switch, the main frequency selected so that the main frequency signal is not substantially reflected at an end surface of the probe, and a second state in which a reference frequency signal having a reference frequency is provided at an output of the switch, the reference frequency selected so that the reference frequency signal is substantially reflected at the end surface of the probe; a first conditioning circuit that receives a frequency provided at the output of the switch and provides a conditioned frequency to the probe; a second conditioning circuit that receives both the conditioned frequency provided by the first conditioning circuit and a reflected frequency received by the probe, and provides a conditioned output based on the conditioned frequency and reflected frequency; and a controller that selectively controls the state of the switch to apply either the main frequency or the reference frequency to the output of the switch, wherein the controller applies the main frequency to the output of the switch, and then subsequently applies the reference frequency to the output of the switch, stores the conditioned output provided by the second conditioning circuit for both the main and reference frequency reflections; and determines tip clearance (d) based on the stored conditioned outputs provided by the second conditioning circuit. a probe that both directs signals toward a turbine blade and receives signals reflected by the turbine blade; circuitry comprising: a switch having a first state in which a main frequency signal having a main frequency is provided at an output of the switch, the main frequency selected so that the main frequency signal is not substantially reflected at an end surface of the probe, and a second state in which a reference frequency signal having a reference frequency is provided at an output of the switch, the reference frequency selected so that the reference frequency signal is substantially reflected at the end surface of the probe; a first conditioning circuit that receives a frequency provided at the output of the switch and provides a conditioned frequency to the probe; a second conditioning circuit that receives both the conditioned frequency provided by the first conditioning circuit and a reflected frequency received by the probe, and provides a conditioned output based on the conditioned frequency and reflected frequency; and a controller that selectively controls the state of the switch to apply either the main frequency or the reference frequency to the output of the switch, wherein the controller applies the main frequency to the output of the switch, and then subsequently applies the reference frequency to the output of the switch, stores the conditioned output provided by the second conditioning circuit for both the main and reference frequency reflections; and determines tip clearance (d) based on the stored conditioned outputs provided by the second conditioning circuit.