Photoelectric fork sensors from autosen work on the basis of optical through beam sensors. Transmitter and receiver are located at both ends of the fork-shaped housing respectively. The detection range is within the fork opening. Transmitter and receiver need not be adjusted because both elements are stationary installed and aligned, thus rendering installation very simple. The buckling resistant housing ensures optimum alignment of transmitter and receiver even under temperature fluctuations and mechanical stresses. The detection of small objects up to the width of 0.4 mm is possible depending on the sensitivity of the receiver. The sensitivity of the photoelectric fork sensors is easily adjusted using a potentiometer.