CONVEX-D Digital Tape Extensometer Datasheet

? Lightweight, dust proof, robust and re-liable construction ? Anti-backlash mechanism ? Sliding latch ? Digital display and its protective window ? Anodized aluminum construction ? New Austrian Tunneling Method (NATM) also compliant with a "design as you moni-tor" FEATURES TAPE EXTENSOMETER CONVEX-D APPLICATIONS The CONVEX-D is a digital tape extensometer which quickly and accurately measures changes in distance between two reference points in any orientation. This design incorporates several im-provements compared to other con-vergence instruments available on the market. Measurement of: ? Mine roof sag ? Tunnel convergence ? Sheet piling deformation ? Slope stability DESCRIPTION The CONVEX-D digital tape extensometer basically consists of a steel survey tape with punched holes, loaded on a reel fixed to the body of the instrument. Among added features to the CONVEX-D, there is: ? A unique anti-backlash tensioning mechanism ensuring a con-tinuous accuracy in time. ? A pivoting latch has been incorporated to lock positively the tape, thus facilitating the instrument's handling. ? A digital indicator has been added in order to accurately read the relative change between two reference points. By turning the rotary protection drum, it is easy to get quick access to the digital display function buttons through the opening provided for this purpose. ? Two hooks are provided, one at the movable end of the tape and the other on the reel frame. ? Tensioning of the tape to a predetermined load is easily done by rotating a large knurled collar until two reference lines are precisely aligned. Visual alignment is optimized by the use of two superimposed magnifying lenses. For an actual measurement, the CONVEX-D is stretched be-tween two reference points consisting of two stainless steel eye-bolts fixed on their respective anchor. Where instrumentation technologies meet ORDERING INFORMATION SPECIFICATIONS INSTALLATION Proper anchoring of the reference points is required to complete an accurate measurement. The anchors, which must be chosen according to the conditions, are either rebars (A) to be grouted in boreholes or expansion shell anchors (B). The eyebolts can also be directly bolted (C) or welded (D) on structural steel beams. To take a reading, the snap hook fixed on the movable end of the tape is attached to one reference point. Moving towards the oppo-site anchor, the tape unwinds until it is possible to fix the hook mounted on the reel onto the second reference point. The slack in the tape is then taken up by winding up the reel and the locking pin located at the front of the extensometer is then inserted into the nearest hole of the tape. The knurled collar is then rotated to tension the tape up to a predetermined value of 133.5 N (30 lbf) corre-sponding to the precise alignment of the two reference lines. The measurement is made by adding the tape and the digital indicator readings. The optional verification frame can be used before a series of readings to verify that the instrument has not been damaged. ACCESSORIES ? Carrying case ? Reference points and anchors ? Verification frame ? Replacement Tape Roctest Ltd. · 680 Birch Street, Saint-Lambert, QC, J4P 2N3 CANADA · Tel. 1-450-465-1113 · Fax 1-450-465-1938 · info@roctest.com · www.roctest.com Products and specifications are subject to change without notice. © Roctest Ltd., 2013. E5062E-131001 CONVEX-D / DIGITAL TAPE EXTENSOMETER Ranges LCD indicator resolution Repeatability Operating temperature 20 m, 30 m, 66 ft. or 100 ft. 0.01 mm or 0.0005 in. ± 0.10 mm or ± 0.005 in. 0°C to 40°C REFERENCE POINTS Eyebolt Diameter Length Stainless steel with two nuts 6.35 mm 50 mm ANC HORS Type A Anchor diameter Anchor length 20 mm 150 mm Type B Drilled hole diameter Drilled hole depth 13 mm 35 mm PART NUMBER DESCRIPTION FR-1062E50100 Aluminum basic instrument without tape FR-1062050200 Verification frame 05-0062VALISE Carrying case 40-1062040100 Reference point with anchor A 40-1062040300 Reference point with anchor B 40-1062040400 Reference point (eyebolt & nuts / anchor C or D) 10-1062000020M 20 m tape 10-1062000030M 30 m tape 10-1062000066F 66 ft tape 10-1062000100F 100 ft tape