Draw Wire Sensors for Harsh Duty?

SL1500 Long Stroke Linear Position Sensor for underwater or subsea hydraulic cylinder use

Here at CPI we’ve developed a name for ourselves when it comes to precision engineered draw wire sensors, made for harsh duty applications. Sensors like our SL1200 draw wire position sensor get the job when other sensors just don’t survive.

But “harsh duty” appears to be an overused term, at least in the hydraulic linear position sensor industry. Recently some of our competitors have touted their “harsh duty” sensors in a variety of really scary(?) applications.

  1. Elevator hydraulics – Yes its really frightening in an elevator shaft where there is no exposure to the outdoors, a huge fan provides abundant air flow, and rain and moisture exposure is all but a distant memory.
  2. Industrial Forklift – Well the weights may be heavy but other than the danger presented by bad driving, how is that harsh duty exactly?
  3. Drawbridge Hydraulics – Well at least here you may get rained on… but the size and stability of a drawbridge, and the linearity of motion preclude some of the most serious durability challenges like vibration, submersion, and in-cylinder deployment.

Other manufacturers tout their “heavy duty” draw wire sensors because the cable is coated with plastic. Or because their enclosure is waterproof. In another case the entire sensor wire length had to be enclosed in telescopically sealed stainless steel housing.   How is that “heavy duty exactly”

On the other hand, when CPI says it has a harsh duty position sensor, we have some very specific ideas about what that means.

  1. Completely Submersible. In seawater. To 5000ft in mining at the sea floor. Go ahead try it, we have.
  2. Completely waterproof. We don’t have any sealed volumes in our assembly and our LVDT is encased in a watertight forming material.
  3. Pressure immune – Our all stainless construction means we can withstand almost any hydraulic pressure. That means we can be deployed internally on hydraulic cylinders on the gas or the oil side
  4. EMI resistant – Our LVDT and signal conditioning electronics are simpler and less susceptible to EMI distortions which affect accuracy.
  5. Accuracy – Our measurement technology is accurate down to 1mm over a 10m stroke length. Let the guy with the plastic coated cable and the rotary encoder try to beat that.
  6. Non-contacting – We think anyone using a potentiometer based measurement electronics has no business calling their sensor “harsh duty”. Yet surprisingly many do.

Whether you are exploring for gas and oil on the ocean floor, or making sure your 100 ton mining shovel is operating correctly, we have a real harsh duty linear position sensor for you.

Call us today to discuss your application.