Method for generating a time delay

In a Time Domain Reflectometry (TDR) measurement system including a housing and an elongate measurement probe and an electronics assembly comprising a transmitter for transmitting a signal to the elongate measurement probe and a receiver for receiving at least a return echo from the signal upon encountering a change in impedance to thereby determine a position of a medium in relation to the elongate measurement probe, a method for generating a time delay between transmit and receive pulses for capturing measurements in a given measurement cycle, the method comprising:

• said electronics assembly initiating a first time-dependent non-linear ramped waveform function and a second time-dependent non-linear ramped waveform function associated with transmit and receive signals, respectively;
• wherein the second time-dependent non-linear ramped waveform function being a relatively slow waveform in relation to the first time-dependent non-linear ramped waveform function, and initiated at a first time prior to initiation of the first time-dependent non-linear ramped waveform at a second time t0;
• comparing the output of the first time dependent non-linear ramped waveform function and the second time-dependent non-linear ramped waveform function;
• activating a receive signal to measure a data point along the waveguide associated with a localized impedance at a third time t1 when the outputs of the first and second time-dependent non-linear ramped waveforms are equal;
• wherein the first and second time-dependent non-linear ramped functions are configured such that their waveform characteristics produces a time delay between time t0 and time t1 that is a linear function of time.