A sensing apparatus comprising: a unitary ultrasound transceiver for transmitting ultrasound signals into a sample and receiving a resultant ultrasound reflection signal from the sample; a detector for processing signals received by the transceiver by comparing the received signal against a reference signal to generate a response signal, the response signal comprising values as a function of time that represent the strength of the match between the received signal and the reference signal at the respective time; and a driver capable of generating a plurality of pre-defined pulse templates, the driver being operable in a use phase to apply: one of selected ones of the pre-defined pulse templates to the transceiver for driving it to transmit ultrasound signals, the selected ones of the ore-defined pulse templates include at least two different pulse templates, each being a different one of the following: i) a pulse template having been selected in a pre-use phase that consists of a single pulse and that, when the transceiver is driven into air in the pre-use phase, generates a response signal having a higher prominence of a primary peak than the response signals generated by any of the other pre-defined pulse templates that consist of a single pulse; ii) a pulse template having been selected in the pre-use phase that consists of two or more pulses and that, when the transceiver is driven into air in the pre-use phase, generates a response signal having a higher prominence of a primary peak than the response signals generated by any of the other pre-defined pulse templates; iii) a pulse template having been selected in the pre-use phase that, when the transceiver is being driven into a solid in the pre-use phase, generates a response signal having a higher prominence of a primary peak than the response signals generated by any of the other pre-defined pulse templates; and iv) a pulse template having been selected in the pre-use phase that, when the transceiver is driven in the pre-use phase, generates a response signal having a higher proportion of its energy in a primary peak than the response signals generated by any of the other pre-defined pulse templates. a unitary ultrasound transceiver for transmitting ultrasound signals into a sample and receiving a resultant ultrasound reflection signal from the sample; a detector for processing signals received by the transceiver by comparing the received signal against a reference signal to generate a response signal, the response signal comprising values as a function of time that represent the strength of the match between the received signal and the reference signal at the respective time; and a driver capable of generating a plurality of pre-defined pulse templates, the driver being operable in a use phase to apply: one of selected ones of the pre-defined pulse templates to the transceiver for driving it to transmit ultrasound signals, the selected ones of the ore-defined pulse templates include at least two different pulse templates, each being a different one of the following: i) a pulse template having been selected in a pre-use phase that consists of a single pulse and that, when the transceiver is driven into air in the pre-use phase, generates a response signal having a higher prominence of a primary peak than the response signals generated by any of the other pre-defined pulse templates that consist of a single pulse; ii) a pulse template having been selected in the pre-use phase that consists of two or more pulses and that, when the transceiver is driven into air in the pre-use phase, generates a response signal having a higher prominence of a primary peak than the response signals generated by any of the other pre-defined pulse templates; iii) a pulse template having been selected in the pre-use phase that, when the transceiver is being driven into a solid in the pre-use phase, generates a response signal having a higher prominence of a primary peak than the response signals generated by any of the other pre-defined pulse templates; and iv) a pulse template having been selected in the pre-use phase that, when the transceiver is driven in the pre-use phase, generates a response signal having a higher proportion of its energy in a primary peak than the response signals generated by any of the other pre-defined pulse templates. i) a pulse template having been selected in a pre-use phase that consists of a single pulse and that, when the transceiver is driven into air in the pre-use phase, generates a response signal having a higher prominence of a primary peak than the response signals generated by any of the other pre-defined pulse templates that consist of a single pulse; ii) a pulse template having been selected in the pre-use phase that consists of two or more pulses and that, when the transceiver is driven into air in the pre-use phase, generates a response signal having a higher prominence of a primary peak than the response signals generated by any of the other pre-defined pulse templates; iii) a pulse template having been selected in the pre-use phase that, when the transceiver is being driven into a solid in the pre-use phase, generates a response signal having a higher prominence of a primary peak than the response signals generated by any of the other pre-defined pulse templates; and iv) a pulse template having been selected in the pre-use phase that, when the transceiver is driven in the pre-use phase, generates a response signal having a higher proportion of its energy in a primary peak than the response signals generated by any of the other pre-defined pulse templates.