Among other things, one or more systems and/or techniques for improving performance of a dispensing system are provided herein. The dispensing system may comprise an emitter and a detector. The emitter may be configured to transmit light (e.g., and/or one or more other signals). The detector may be configured to measure light, for example. The detector may determine a first measurement of light while the emitter is not transmitting light. The detector may determine a second measurement of light responsive to the emitter transmitting light. The detector may determine a third measurement of light based upon a comparison of the first measurement of light with the second measurement of light. The detector may be direct current (DC) coupled while determining the third measurement of light.