A particle concentration measurement system includes a first window and a second window separated by a sensing volume. The system also includes one or more supports to provide structural support for the first window at a first end and for the second window at a second end, opposite the first end, of each of the one or more supports. The sensing volume is defined by the one or more supports and the first window and the second window is open to an environment of the particle concentration measurement system adjacent to the one or more supports such that particle-laden gas from the environment that includes particles mixed with other materials enters the sensing volume. A first compressed gas orifice directs compressed gas onto the first window to clean the first window and a second compressed gas orifice directs the compressed gas onto the second window to clean the second window.