ðeɪ ɑːɹ bˈeɪst ɔnðə mˈaɪkɹoʊpˌaʊɚɹ ˈɪmpʌls ɹˈeɪdɑːɹ æz ðɪ ˌʌndɚlˈaɪɪŋ tɛknˈɑːlədʒi, ænd stˈʌd fˈaɪndɚz jˈuːzɪŋ ðɪs tɛknˈɑːlədʒi wʌz ɪnvˈɛntᵻd baɪ tˈɑːməs mək jˈuːən ænd pˈæʔn̩ɾᵻd ɪn nˈaɪntiːnhˈʌndɹɪd nˈaɪnti fˈaɪv.
They are based on the micropower impulse radar as the underlying technology, and stud finders using this technology was invented by Thomas McEwan and patented in 1995.