The DIST (Distributed Impedance Sensor Technology) sensor is capable of operating in harsh environments, such as at temperatures in excess of 225°C, high radiation, high magnetic fields, vibration and high-shock. This harsh environment sensor requires only one wire for both power and output signal and can transmit the signal over lengths in excess of 10 meters. It is an absolute linear encoder which can measure lengths from a few millimeters up to one meter while maintaining accuracies in the micron region. The output of the sensor is frequency, a digital signal, and is not sensitive to noise and attenuations in the signal path. The sensor requires only a standard frequency meter to interpret the position. It requires no magnets or magnetic material and is insensitive to external magnetic fields.
Why is the DIST sensor considered a harsh environment 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 225oC 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 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 single signal wire output from the DIST sensor is also very beneficial when operating in a high pressure environment. Conductor transitions from high to low pressure are expensive, vulnerable (usually glass seals) and could cause distortion of analog signals. With only one wire, these problems are minimized.
Download our white paper Applicability of DIST Technology in Harsh Environments to read in further detail about why DIST sensors are the best choice when you are looking for a harsh environment sensor.
