BOLT-Tester
Non-destructive testing equipment for primary screening
BTS(BOLT-Tester) is developed in 2012 after the collapse at SASAGO Tunnel on the Chuo Expressway in Japan. Visual inspection and hammer sound testing are main inspection methods for maintenance and management of anchor bolts in a tunnel. However, these methods have some issues in regard to objectivity and reliability of the results. Pull out testing is also one of a testing method for the soundness test of anchor bolts, however, this method have also some issues in regard to cost and time, and there is a risk to damage the anchor bolt. BTS is simple and cost effective non-destructive testing equipment that solves those issues. BTS measures a waveform of impact force to evaluate the soundness of anchor bolt.
Contents
1.Applications
2.Size of hammer
3.Specification
4.How to Use
5.Basic Principle
6.Typical Measured Waveforms
Applications
〇Soundness testing for post-installed anchor bolt
〇Looseness testing for bolts and nuts
〇Looseness testing for wheel bolts
Size of hammer
It is recommended to change the size of hammer according to the size of object to be measured.
BOLT

BOLT-Tester(Large)　　(Left)　⇒　Weight: 1,400g Target size: M20 to M24
BOLT-Tester(Standard) (Center)⇒　Weight: 420g Target size: M12 to M20
BOLT-Tester(Small)　　(Right) ⇒　Weight: 190g Target size: M8 to M12
Specification
Model Name
BOLT-Tester
Applicable Standard
NETIS (HK-180001-A)
Storage case dimensions
390mm x 240mm x 130mm
Device
106mm x 40mm x 11mm
①Weight of Hammer (Large)
②Weight of Hammer (Standard)
③Weight of Hammer (Small)
①1,400g
②420g
③190g
Waveform Measurement
Sampling clock: 0.5µs, Measuring time: 2 ms
Power supply
Bus-powered (up to 350mA)
Connection to PC
USB connection with Windows PC
Measurement data
Recorded as a text format
Accessories
Storage case
USB cable (A-A male-female, 1m)
CD-ROM(Device driver, application and user manual)
How to use
Basic Principle
When an anchor bolt is correctly installed, the bolt behaves elastically and back to original position after the impact by the hammer. The more a bolt is firmly installed, the more the impedance (modulus of elasticity) becomes large. On the other hand, in case the bolt is not firmly installed, modulus of elasticity becomes lower and measured waveform will be disturbed. Moreover, adhesion becomes more lower, the bolt moves and strikes concrete, and measured waveform becomes two peaks. BOLT-Tester evaluates soundness of an anchor bolts by analyzing the measured waveform.
Example of the waveform
●Waveform of stable anchor bolt Measured waveform becomes most likely symmetry. Shape of the waveform becomes slightly disturbed depending on the condition of target bolt, number of peak is only one.
●Waveform of a bit deformed anchor bolt Peak of the waveform becomes wider as a response from the bolt is delayed.
●Waveform of loose anchor bolt Peak of the waveform becomes two due to the delay in a response from the bolt.