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Crack Meter
Kingmach Crack Meter include the JMDL-21XXAT Smart General-Purpose Displacement Meter, a compact instrument for relative displacement and expansion joint movement. The product is used in buildings, railways, transportation works, hydropower structures, dams, and bridge projects where two structural components may move against one another. Listed ranges include 50 mm and 100 mm, with 0.01 mm resolution and 0.5%FS accuracy. The meter is based on inductive frequency modulation, which supports high sensitivity, stable long-term observation, and low temperature influence. A built-in memory chip stores sensor model, serial number, calibration coefficient, time, temperature data for temperature versions, absolute displacement, relative displacement, and zero-point value. It can save 800 measurement results, which is useful when checking site history after construction stages or weather events. When connected to an integrated tester or automatic acquisition system, readings can be reviewed quickly without relying on manual gauge notes. During project setup, the measuring point should be matched with the expected travel direction, available mounting space, cable route, and required acquisition interval. This prevents a short-range joint instrument from being used on a long-travel point, or an exposed sensor from being placed where an embedded anchor is needed. It also helps the monitoring team set a baseline that can be defended during acceptance and later maintenance review.
Application of Crack Meter
In foundation pit and deep excavation projects, Crack Meter are used to watch retaining walls, soldier piles, soil nails, nearby pavements, basement walls, and adjacent structures as excavation stages remove support from the ground. The main site concern is not only how far one point moves, but whether movement grows after each excavation layer, support installation, dewatering step, or backfill stage. Kingmach JMDL-32XXAT single-point bedrock meters can measure embedded displacement at a selected reference layer, while JMDL-22XXAT crack gauges follow opening at nearby structures or retaining elements. JMDL-52XXADT differential meters provide high-resolution relative movement at joints or structural interfaces, and JMLS-22XXADT wire rope sensors can cover longer exposed paths where access is available. A useful pit monitoring plan records excavation depth, support timing, groundwater level, construction vibration, and surrounding building observations beside each displacement curve. This helps engineers distinguish bracket disturbance from real ground movement, and it supports faster decisions when a wall, road edge, or adjacent building begins to respond to excavation. During review, the same point should be compared with nearby settlement, tilt, support force, groundwater, and inspection notes so the movement is interpreted as part of the excavation behavior rather than as a single isolated value. during maintenance.
The future of Crack Meter
Future Crack Meter will need to serve both precision monitoring and construction-speed decisions. A long-term bridge joint may need high precision differential measurement over many years, while a high-formwork support may need fast warnings during a short concrete pouring window. Kingmach already separates these needs through product forms: JMDL-52XXADT for high precision relative displacement, JMDL-49XXAT for formwork and steel wire displacement, JMDL-24XXAT for flexible geogrid deformation, and JMLS-22XXADT for long travel draw-wire monitoring. As monitoring platforms mature, project teams can select sampling intervals, warning levels, and report formats by construction risk rather than using one schedule for every point. This will make displacement data more actionable for site managers, not only for later technical reports. The strongest systems will still depend on careful installation, because digital tools cannot correct a loose bracket, wrong range, or poorly recorded baseline. Clear reporting will make displacement monitoring more useful for non-specialist decision makers while preserving the detail engineers need.
Care & Maintenance of Crack Meter
For embedded Crack Meter such as multipoint and bedrock displacement meters, maintenance depends heavily on installation records because the sensing parts may not be visible after grouting or backfilling. For JMDL-31XXAT multipoint meters, keep drilling depth, anchor head depth, grouting date, point number, cable route, and baseline readings in one record. The system may monitor three to five points, so channel naming must be exact. For JMDL-32XXAT single-point bedrock meters, record flange position, tie rod condition, anchor point, PVC pipe route, and expected movement direction. During service, compare adjacent depths rather than reading each channel alone. A shallow layer moving while deeper layers remain steady has a different meaning from full-depth displacement. Do not pull or shorten cables during cabinet work, and protect exposed sections from water, rodents, sharp edges, and construction traffic. Keep the installation photo, point number, zero value, and expected movement direction with the commissioning record for later review. If a reading changes after maintenance work, inspect the base, anchor, cable, and cabinet before assuming the structure itself has moved.
Kingmach Crack Meter
Crack Meter help engineers separate normal movement from structural risk. A bridge expansion joint may move with temperature, a tunnel lining may shift after excavation, and a slope may creep slowly before an alarm condition appears. Kingmach displacement products use several sensing routes, including inductive frequency modulation, differential coil measurement, magnetostrictive sensing, draw-wire conversion, and GNSS-based displacement tracking. Ranges can start at 20 mm for joint monitoring and extend to 2000 mm for draw-wire applications, while selected smart models store model data, serial numbers, calibration coefficients, zero values, temperature, and hundreds of measurement records. This makes the reading easier to trace during acceptance, maintenance, and later review. For a project buyer, the practical question is whether the movement point is exposed, embedded, multi-depth, long-distance, waterproof, or tied to geogrid. Kingmach provides different forms for those different site conditions. The point should be named on the drawing, linked with its cable route, and checked against the expected movement direction before the first automatic reading is accepted. For daily review, the reading should be compared with nearby points, recent weather, site operations, and any loading event that could explain the movement.
FAQ
Q: Which Crack Meter fit crack monitoring?
A: The JMDL-22XXAT Smart Crack Gauge is designed for cracks, joints, and expansion joints in bridges, buildings, roads, railways, dams, tunnels, and slopes.
Q: What ranges does the crack gauge list?
A: Listed models include 20 mm, 50 mm, 100 mm, and 200 mm ranges, with 0.01 mm resolution on the 20 mm to 100 mm versions and 0.05 mm on the 200 mm version.
Q: How many records can the crack gauge store?
A: Product information states that it can save up to 600 measurement results, including time, temperature for temperature versions, displacement values, and zero-point value.
Q: What installation details matter most?
A: Base stability, rod alignment, connector sealing, cable protection, and a clear zero reading matter more than a polished-looking installation.
Q: Can it be used for long-term observation?
A: Yes. The product is described for long-term monitoring, especially where crack width changes need stable and repeatable measurement.
Reviews
Andrew Lee
The visualization software is intuitive and powerful. It helps us analyze monitoring data efficiently.
Christopher Martinez
Very satisfied with the readouts & data loggers. User-friendly interface and supports multiple sensor inputs.
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Evelyn***@gmail.comSouth Africa
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Dear team, we are interested in your readouts & data loggers compatible with multiple sensors. Do yo...