Differential temperature surface sensor, comprising a first surface acoustic wave device and a second surface acoustic wave device, each surface acoustic wave sensor comprising a piezoelectric substrate (12, 22), having a propagation surface (13, 23), and a resonator (14, 24) having a transducer (15, 25) laying on said propagation surface, said first and second surface acoustic wave devices (10, 20) being independent one from the other in terms of surface acoustic wave propagation, characterized in that: - said first surface acoustic wave device, comprises: - a first piezoelectric substrate formed from a (YXw/ t) φ / θ / ψ cut of a Langasite crystal, where φ is equal to 0 ± 5°, θ is equal to 55 ± 20° and ψ is equal to 32.5 ± 7.5°, said first piezoelectric substrate having a first propagation surface; - a first resonator having a first transducer laying on said first propagation surface and having two sets of interdigitated first electrodes formed from an electrically conductive material having a high melting temperature; - said second surface acoustic wave device, comprising: - a second piezoelectric substrate, formed from a (YXw/ t)/ φ / θ / ψ cut of a Langasite crystal, where φ is equal to 0 ± 5°, θ is equal to 5 ± 20° and ψ is equal to 0 ± 7.5°, said second piezoelectric substrate having a second propagation surface; - a second resonator having a second transducer laying on said second propagation surface and having two sets of interdigitated second electrodes formed from an electrically conductive material having a high melting temperature. - said first surface acoustic wave device, comprises: - a first piezoelectric substrate formed from a (YXw/ t) φ / θ / ψ cut of a Langasite crystal, where φ is equal to 0 ± 5°, θ is equal to 55 ± 20° and ψ is equal to 32.5 ± 7.5°, said first piezoelectric substrate having a first propagation surface; - a first resonator having a first transducer laying on said first propagation surface and having two sets of interdigitated first electrodes formed from an electrically conductive material having a high melting temperature; - a first piezoelectric substrate formed from a (YXw/ t) φ / θ / ψ cut of a Langasite crystal, where φ is equal to 0 ± 5°, θ is equal to 55 ± 20° and ψ is equal to 32.5 ± 7.5°, said first piezoelectric substrate having a first propagation surface; - a first resonator having a first transducer laying on said first propagation surface and having two sets of interdigitated first electrodes formed from an electrically conductive material having a high melting temperature; - said second surface acoustic wave device, comprising: - a second piezoelectric substrate, formed from a (YXw/ t)/ φ / θ / ψ cut of a Langasite crystal, where φ is equal to 0 ± 5°, θ is equal to 5 ± 20° and ψ is equal to 0 ± 7.5°, said second piezoelectric substrate having a second propagation surface; - a second resonator having a second transducer laying on said second propagation surface and having two sets of interdigitated second electrodes formed from an electrically conductive material having a high melting temperature. - a second piezoelectric substrate, formed from a (YXw/ t)/ φ / θ / ψ cut of a Langasite crystal, where φ is equal to 0 ± 5°, θ is equal to 5 ± 20° and ψ is equal to 0 ± 7.5°, said second piezoelectric substrate having a second propagation surface; - a second resonator having a second transducer laying on said second propagation surface and having two sets of interdigitated second electrodes formed from an electrically conductive material having a high melting temperature.