lvdt linear variable displacement transducer

For fine crack monitoring in concrete or rock, a ±5 mm or ±10 mm stroke usually gives enough travel and good resolution. If the crack is expected to open wider, ±25 mm or ±50 mm makes more sense. Let the expected movement plus a safety margin drive the selection; don’t oversize too much because you lose resolution on small displacements.

Standard units with IP67 sealing handle splashes and temporary submersion, but for permanent immersion we configure the transducer with IP68 rating—this means double O-ring seals, a pressure-tight cable gland, and often a vented cable if the water column is deep. Let us know the water head and we will quote accordingly.

Most models output 0-5 V or 4-20 mA, which any logger with differential or single-ended analog inputs can read. We supply a wiring schedule with the sensor. Power is usually 9-28 V DC. If you are using a Campbell Scientific or similar logger, a simple voltage measurement instruction is enough; no bridge completion or excitation other than DC power.

Yes. Rod-end bearings (eyelet fittings) are common for tie-bar or structural member attachments. Spring-loaded probes are useful when you need to maintain contact with a surface that may move away. Both can be specified when ordering, and we can also machine custom mounting feet if you send a sketch.

For standard modifications like a non-stock cable length or connector change, a couple of weeks is realistic. If the body needs machining alterations or a new stroke range calibration, figure three to four weeks. We always confirm after we review the requirement, so you are not guessing.