A system and method for volumetric metering on a sample processing device. The system can include a metering reservoir, and a waste reservoir positioned in fluid communication with a first end of the metering reservoir to catch excess liquid from the metering reservoir that exceeds a selected volume. The system can further include a capillary valve in fluid communication with the second end of the metering reservoir to inhibit liquid from exiting the metering reservoir until desired. The method can include metering the liquid by rotating the sample processing device to exert a first force on the liquid that is insufficient to move the liquid into the capillary valve, and rotating the sample processing device to exert a second force on the liquid that is greater than the first force to move the metered volume of the liquid to the process chamber via the capillary valve.