Crack and Joint Meter Model EDE-VXX (MTI.EWS.ER.M-EDE-VXX). The vibrating wire displacement sensor can be used in uniaxial/biaixial/triaxial crack meters or joint meters, borehole extensometers (BHE) and soil extensometers. The sensor is available in following variants:
1. EDE-VXX-SC with side cable (suitable for crack gage)
2. EDE-VXX-RC with rear cable (suitable for BHE)
3. EDE-VXX-WP waterproof For use as a crackmeter, the EDE-VXX-SC version of sensor is provided with spherical bearing joints at the two ends and anchors for fixing the joint rods to brick, concrete or rock surfaces. The retractable shaft of model EDE-VXX vibrating wire displacement transducer has a 10 mm long M6 x 1 male thread. When used in borehole extensometer the EDE-VXX-RC version of sensor is used. The sensor is positioned with respect to the reference plate to set the zero reading in following ways:
• If extension is expected, the zero reading of the sensor is set by extending it by around 10 mm.
• In case only compression is expected, the zero reading is set by extending it by around 10 mm less than the range.
• If required, the zero reading of the sensor can also be set at any intermediate position. The displacement sensor converts the mechanical displacement to an electrical frequency output. The frequency output can be accurately measured by any vibrating wire readout unit. The data can also be automatically collected at desired frequency, stored and transmitted to remote server by a suitable datalogger.
Crack and Joint Meter Model EDE-VXX
• Sensor Type: Vibrating wire
• Parameter: Displacement
• Range: 15, 25, 50, 100 or 150 mm
• Key Testing / Calibration: Thermal cycling (-20 to +80°C), Thermal variation data, accuracy test, waterproof test for WP version
• Key Feature/Advantage: Versatile sensor, can be used reliably in harsh environment or under deep water
• Protection (Waterproofing): IP-68, water resistant up to 40 mwc, waterproof version up to 100 mwc
• Dimension (mm): Depends on range
• Sensitivity: 0.02 % fs
• Accuracy: 0.2 % fs standard 0.1 % fs optional 0.5% fs (for 150 mm range)
• Non linearity: ± 0.5 % fs
• Resolution: 0.025% fs
• Temperature limit: -10 to 800C (operational)
• Temperature effect: Zero (maximum): 0.01% fs/°C Span (maximum): 0.03% fs/°C
• Thermistor: YSI 44005 or equivalent (3 kOhms at 25°C)