The utility model discloses a WTS transmits four arm caliper survey instruments, it includes power supply circuit, processing circuit and signal acquisition circuit, wherein signal acquisition circuit includes acquisition circuit, data processing and transmission circuit and communication circuit. The utility model discloses can can constitute the simplest WTS interface well diameter measuring system with 3514 the spread of the rumours communication nipple joints, simultaneously, processing circuit and signal acquisition circuit are together integrated and install in the thermos of instrument, have reduced that the signal acquisition and processing piece is fragile to receive temperature and the virtual scheduling problem that connects with junction seal point, the utility model discloses a structural design has improved the temperature resistance behavior of whole circuit device, and simple structure easily maintains.