A device including a reservoir filled with fluid, a frame, and a resilient rolling seal to prevent the fluid from reservoir from escaping, even while the device is moved along a surface. The purpose of this device is to deploy a sensor which is housed within the reservoir. The device is thus capable of maintaining a reservoir of fluid around a sensor or probe and allow the sensor or probe to remain immersed in the fluid, while also remaining in contact with the surface in which the device is moved along. The sensor preferably resides in a fluid couplant of the device. Because the fluid and the sensor reside in the reservoir and because that reservoir is effectively sealed, there is very little loss of fluid, and the amount of fluid needed to conduct testing is dramatically decreased.