In use, they mount into a hole in one flat surface, and measure the distance to a nearby conductive flat surface parallel to the first.
There are three basic types:
- KD-1925
1.27mm range
0.76μm resolution
5000psi max - KD-1950
3.81mm range
1.3μm resolution
3500psi max - KD-1975 (see photo)
5mm range
2.5μm resolution
3500psi max
Laser-welded hermetically-sealed Inconel (nickel chrome alloy) housings rebuff many corrosive gasses and liquids, oil and dirt, and some radiation – as do the rigid Inconel sleeved mineral-insulated connecting leads.
“Originally designed for NASA and the nuclear power industry, these sensors provide non-contacting measurement of conductive surface motion with accuracy and reliability under the most hostile operating conditions,” according to the company.
Inside the corrosion-resistant case, each sensor two coils and senses eddy currents within the conductive target through its own metal front face by impedance variation. “The symmetrical design of the dual coils compensates for constant and slowly changing temperatures,” said the company.
KD-1975, for example, has a body that measures 19mm in diameter, is linear within 1% and operates over 0-2.5kHz (3dB). Nominal output is 0 – 2Vdc.
All units are designed to work with the company’s KDM-8200 series of rack-mountable signal conditioners, which can have between 1 and 8 channels.
Each sensor model has a similar cousin designed for magnetic targets – whose part numbers have an ‘M’ suffix.
