Available Outputs

Both the housed (DIST A) and un-housed (DIST B) configurations are available with a variety of outputs.

Analog Output Options

4-20 milliamps
0.5 – 4.5 VDC
1 – 5 VDC
0 – 10 VDC

Frequency Output

LRT Sensors frequency output is unique in the industry and is covered by our pending patent POSITION SENSING HEAD WITH REDUNDANCY.  It 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 range.  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. The electronics, a simple circuit consisting of a single transistor, produces a frequency that oscillates in the 2-4 Mhz region.  The output is linear and can easily be converted to a digital signal for further processing.

Having an output that is a digital frequency rather than a voltage has many advantages.  The amplitude of a frequency signal in the DIST system is not significant so long as it remains above the threshold of detection.   Typical inductive sensors have analog outputs which make them susceptible to noise, attenuations and other distortions.   They require that the system electronics be near to the sensor or have extensive correction software to compensate for these errors.  Because of these and other problems it is difficult for an analog sensor to have accuracies better than one part in one-thousand of (0.1%) of full scale.  The DIST sensors’ accuracy is one part in one-million (0.0001%) of full scale. The frequency signal can be replicated and sent over separate wires for redundancy or multiplexed giving it great flexibility in its mode of transmission.  In addition, since the signal analyzer is nothing more than a frequency counter, the DIST sensor does not lose its calibration if it becomes necessary to change the electronics in-the-field.

Because of the simplicity of the frequency output, the sensor can be optionally offered for harsh environments:

• Temperatures up to 225°C
• High Pressures – Hydraulic Cylinders or Undersea Applications
• High Radiation Areas

A sensor with a frequency output can operate with a single wire (plus a ground) to transmit information to a remote computer.  The signal wire can be 10 meters in length, and longer with repeaters, allowing great flexibility in locating the signal analysis electronics.