The void fraction is one of the most important quantities in experimental studies of two-phase flow. Two simple and economical techniques to determine this quantity are developed and discussed. The improved impedance method, in which a high-frequency processing circuit is developed to measure and amplify the voltage changes between the electrodes, is the first method. The differential pressure (D/P) method, in which a commercial differential pressure transmitter is used to determine the static pressure of two-phase flow, is the second method. Experiments including tests in vertical and horizontal pipes for the impedance method and a vertical pipe test for the D/P method have been performed. Furthermore, theoretical models of these two techniques are developed. The test results show that most of the measured void fractions are within a 20% error band compared with the actual void fraction.