As for pulse tube refrigerators, it is difficult to understand the phenomena in the pulse tube because gas in the tube oscillates, exchanging heat with the wall. So it is necessary to measure the temperature profile in the pulse tube and to compute the enthalpy flow in order to understand the phenomena. We adopted a measurement using Rayleigh scattering in order to measure the temperature profile in the pulse tube. We made a pulse tube refrigerator with a quartz-glass pulse tube. The pulse tube refrigerator was refrigerated in air, with only the regenerator covered with insulators. Therefore the pulse tube works as a heat exchanger. Under the above conditions, the temperature profile in the pulse tube has been measured and visualized. Enthalpy, work and heat flows have been calculated from the measured temperature profile. The calculated work flow plus the calculated heat flow is equal to the calculated enthalpy flow. The calculated enthalpy flow shows the level of heat exchange in the pulse tube.