This paper presents experimental results comparing the detected acceleration values from sensors measuring American football helmet impacts. The sensors used in the study include a laser vibrometer, a research grade accelerometer, an Impakt Protective, Inc. Shockbox® Football Helmet Sensor, a Reebok CHECKLIGHT™ sensor, and a Pressure Analysis Company, Inc. prototype sensor. A human head model was placed into a Riddell helmet and this helmet was then affixed to a pendulum. The helmet was pulled back and allowed to collide with a large granite block to create a frontal, forehead area impact on the helmet. A comparison is made of the detected accelerations from these sensors with a wide range of impact velocities, along with a repeatability determination of several measurements made for two selected impact velocities.