9420 VW Crackmeter

Introduction

The Model 9420 vibrating wire crack gauge (tensile type) is used to monitor the expansion and contraction of cracks, including:

• Joint of dam concrete structure
• Surface cracks in rock tunnels
• Surface cracks on bridge piers
• Surface cracks on beams and columns of MRT viaduct
• Joint of concrete structures

The Model 9420 vibrating wire crack gauge (tensile type) uses a vibrating wire displacement sensor to measure cracks. The crack gauge contains a set of vibrating steel wire sensitive components, with one end of the steel wire fixed and the other end connected to a spring tension rod. When the crack deforms, it drives the movement of the tension rod, causing the spring to change the vibration frequency of the steel wire. The magnitude of this vibration frequency is proportional to the size of the crack opening and closing. The Model VW405 reader or automatic recording system can measure and read the vibration frequency data of the crack meter.

Specifications

Parameter	Value					Unit
Model	9420-25	9420-50	9420-100	9420-150	9420-200
Measurement Range	25	50	100	150	200	mm
Body Length	195	195	250	400	400
Nonlinearity	< 0.5					%FS
Sensitivity	0.025
Thermistor	3					KΩ
Temperature Range	-20～80					℃
Cable Length	2m (length can be customized)
Cable Material	4 core / 22 AWG / PE insulation / PVC outer cover
Housing Material	300 series stainless steel
Corresponding Reader Model	VN2004/VN2008/VN2016/VN2024