Text this: Simple laboratory-made piezoelectric sensors for detection of selected gaseous and/or vapor sample

  ______    _____     _  __    _____     _____   
 /_____//  |  ___||  | |/ //  |  ___||  |__  //  
 `____ `   | ||__    | ' //   | ||__      / //   
 /___//    | ||__    | . \\   | ||__     / //__  
 `__ `     |_____||  |_|\_\\  |_____||  /_____|| 
 /_//      `-----`   `-` --`  `-----`   `-----`  
 `-`