crack meters

A crack meter is specifically designed to be mounted across an existing crack or joint, normally with two anchor points on either side. It measures only the opening or closing movement perpendicular to the crack plane. Displacement transducers are more general and can measure linear movement between any two points, but they often lack the built-in mounting brackets and weather protection that crack meters come with.

Look at the crack’s maximum expected movement, not just its current width. For seasonal opening in concrete, add 50% to the estimated annual peak-to-peak displacement. For new construction where thermal or settlement cracks are anticipated, engineers often pick 25–50 mm ranges. Long-term monitoring on large structures like dams might require up to 100 mm or more. Give yourself headroom so the sensor doesn’t bottom out.

Most Kingmach crack meters are sealed to IP67 or higher, meaning they handle temporary submersion and constant dampness. If you’re monitoring a rock face behind a waterfall or a tunnel invert that’s often wet, confirm the IP rating and the cable gland protection rating. For permanent submersion, extra sealing steps or specialized submersible models may be needed.

Vibrating wire models can be read with a portable handheld reader, which is simple for manual weekly checks. For automated logging, connect to a compatible datalogger that stores readings at set intervals. Our sensors with 4–20 mA or RS485 outputs plug directly into data acquisition systems, SCADA networks, or wireless nodes. Choose based on how often you need readings and your existing site infrastructure.

Anchor the bracket into sound concrete away from the crack edges, where spalling might occur. Use chemical anchors or expansion bolts rated for the wall’s material. Make sure the sensor body is parallel to the direction of movement you want to measure – even a slight angle can introduce off-axis errors. Protect the cable with conduit if it’s exposed to traffic or sunlight, and record the initial zero reading as soon as the meter is fixed before any more load or weather cycles hit the structure.