The DMM600 measures volumetric water content of organic forest floor material. It is a portable, battery-powered device that uses measurement methods sensitive to the dielectric properties of the material being measured.

The DMM600 consists of a cylinder that houses the electronics, a sample chamber with a compression knob, and an LCD readout. To measure duff water content, the sample is placed in the sample chamber and the compression knob is turned until an audible indicator signals the sample is properly compressed and the measurement is complete. Total time for measurement is about 30 seconds. Readings are displayed in real-time only; measurements are not stored.

The DMM600 comes with a sieve and case. The sieve fits in the opening of the sample chamber. Duff is moved through the wire mesh of the sieve to break up large fragments and improve measurement accuracy in duff materials with a large range of fragment sizes. The case eases transport and provides storage for the sieve and small items such as a spare battery, screwdriver, and pencil.

The CS505 Fuel Moisture Sensor consists of an epoxy-encapsulated electronics package. It uses Time Domain Reflectometry Technology to measure the moisture content of the 10824 10-hour Fuel Moisture Stick. The 10824 is a USFS-specified, 10-hour, ponderosa-pine dowel that is purchased separately.

The 10824 10-hour Fuel Moisture Stick is constructed from the same carefully selected USFS-standard ponderosa dowel as the traditional weighing fuel-moisture rack. No artificial materials (e.g., epoxy sealant) are added to the dowel that would adversely influence the natural behavior characteristics of it. Because the complete dowel surface is accessible for moisture exchange, the response of the CS505 is similar to that of the traditional weighing racks.

To optimize probe-to-probe repeatability and to allow probe interchangeability without individual calibration, two additional sorts are performed on the dowels before they are selected to be used as a sensor. First, the dowels are sorted dry by density to improve accuracy in the dry range of 0 to 15 percent. Second, the dowels are sorted after a 50-minute soak by weight to reduce probe-to-probe time response variation and minimize variability in the wet range of 20 to 50 percent.

The KH20 is a highly sensitive hygrometer designed for measurement of rapid fluctuations in atmospheric water vapor. It does not measure absolute concentrations. Routine maintenance is required to keep source and detector windows free of "scale."