The DIST (Distributed Impedance Sensor Technology) sensor is a high temperature position sensor that is capable of operating in temperatures in excess of 225°C.
Why Does The DIST Sensor Work As A High Temperature Position Sensor?
The electronic section of the DIST sensor requires only a single active device (an inverter) which is available commercially in versions that can operate at 225°C and high radiation. The output frequency can be piggybacked on the DC power so that only one wire is required and the receiver can be located remotely. All of this circuitry (along with a temperature sensor) easily fits on a very small circuit board. This gives the DIST sensor the ability to operate in harsh environments such as high temperature with only a single wire (plus a ground) to transmit information to a remote computer. Additionally, the ability to have a signal wire in excess of 10 meters in length, and longer with repeaters, allows great flexibility in locating the signal analysis electronics.
The DIST sensor utilizes a single dual-helix coil (not a ratio of coils as in the LVDT) that is slightly more sensitive to temperature changes than comparable technologies. To compensate for this change, the DIST sensor has an integral temperature sensor whose output is converted to a lower frequency, transmitted on the single wire and used to correct these changes. When calibrated with high temperature use in mind, the errors associated with extreme temperature become insignificant.
DIST sensor is a simple, economical and compact device that can make accurate and reliable linear measurements in almost any environment with only a single wire for power and signal. It is currently available in custom configurations for OEM users and is also available off-the-shelf in standard configurations.
To learn more about the technology behind the DIST sensor as a high temperature position sensor, download our white paper Applicability of DIST Technology in Harsh Environments.