Olson CTG-2 Concrete Thickness Gauge

TRSC uses the Olson CTG-2 on investigations where concrete thickness must be measured from one-side access only (typical for slab-on-grade where back-face access is impossible, podium decks where the soffit is concealed by services or finishes, and bridge deck inspections from the wearing surface) and on investigations where internal delamination zones must be mapped without coring. The principal advantage of impact-echo over UPV in these scenarios is the single-face access — UPV requires through-element transducer placement which is often impractical, while impact-echo operates from the accessible face only. Two operational notes: first, concrete thickness measurement requires the wave-velocity assumption to be calibrated against a known reference (typically a cored hole at the start of the survey); without calibration the thickness reading is indicative only. Second, defect identification requires interpretation of the spectral response — TRSC personnel are trained in impact-echo signal interpretation and cross-check ambiguous readings with parallel UPV or borescope investigation. The CTG-2 is a hand-held instrument that complements rather than replaces the more comprehensive impact-echo systems used in dedicated bridge-deck inspection programmes; for TRSC's typical building and infrastructure scope it provides the appropriate balance of capability, portability and cost. On large-scope bridge-deck or podium-deck condition assessments where high-density delamination mapping is required across hundreds of square metres, TRSC engages a specialist NDT sub-contractor with vehicle-mounted impact-echo / impulse-response array systems, and reserves the CTG-2 for spot-verification, confined-space and small-scope investigations where the hand-held form factor is decisive — typically slab-on-grade investigations under 200 square metres of survey area.