Abstract: An impulse hammer of a variable sensitivity type permitting the user to instantly select from at least three different full scale operational ranges which includes an elongated handle having a plastic grip at one end and a head carried at its other end normal thereto. A head extender is detachable carried on one end of the head while a force sensor terminating in an impact tip is fixedly carried on the opposite end. An electrical circuit couples to a transducer in the force sensor and communicates through the head and handle with a coaxial connector located at the end of the handle. An impedance converter is included in the circuit transforming the high impedance signal from the transducer to a low impedance output voltage. A manual selector switch changes the voltage gain of the sensor to avoid amplification of noise level.