The TMS sensors have a circular pattern of interdigitated electrodes that utilize a fringing field to measure the material in contact, similar to the fringing field measurement of our implantable sensors. The electrodes are silver palladium embedded in a ceramic substrate. The electrode spacing of 20 mils provides a fringing field measurement penetration 20 mils into the material.
The constant geometry electrode pattern makes them useful for applications in which sample thickness may vary. They may be used with a filter in materials with conductive fibers such as graphite. The fringing field measures the resin which saturates the filter and not deep into the conductive composite. All TMS sensors have a thermocouple located just below the sensor surface.
The Monotrode sensors consist of a single tool steel, chrome plated electrode mounted in a ceramic substrate. The sensor electrode couples with the opposite mold surface or the sensor sheath which acts as the second electrode. A second sensor is not required. The Monotrode sensor makes a bulk measurement - measuring through or deep into the part. The monotrode sensor is designed for repetitive molding for such applications as SMC/BMC/RTM. Most monotrode sensor have a thermocouple located just below the sensor surface.
DFS sensors can be either TMS or Monotrode configuration and can be used for liquid applications such as batch reactions or continuous flow measurements in laboratory or production applications.