Method Comparison

Method Comparison

Experiment for Comparing Conventional Methods and KUMONOS

1.Condition

Subject:3 people who got 2-day technical training
What Is to Be Measured:5 simulated cracks on paper
Place of Experiment:50m away from what is to be measured
Number of Times:1

2.Method

    1. Set the simulated cracks (Figure.1) on the wall as shown by Figure.2.
    2. Measure the position and the shapes of cracks in the two ways below.
      – Observe the cracks through a pair of binoculars and sketch them (Figure.3)
      -Measure cracks using KUMONOS (Figure.4)
    3. Draw a figure on AutoCAD
    4. Overlap the figure with the simulated cracks and analyze the defferences

3.Result

Comparison Accuracy (Position and Shape)

KUMONOS Conventional Method
1mm ~ 3mm 28mm ~ 46mm

*Accuracy: The difference between the figure and the cracks to be measured

The Result of Measuring the Widths (Only Using KUMONOS)

Crack No.
Actual Width (mm)
Result
Accuracy
A
B
C
Average
1
0.20
0.22
0.22
0.18
0.21
±0.02
2
0.40
0.42
0.36
0.44
0.41
±0.04
3
0.09
0.10
0.14
0.14
0.13
±0.05
4
0.20
0.22
0.18
0.22
0.21
±0.02
5
0.30
0.32
0.29
0.32
0.31
±0.02

*Accuracy: The difference between the figure and the cracks to be measured

KUMONOS is approximately 10 times as accurate as the conventional
method in inspecting the position and the shape of a crack.

The width accuracy is within 0.05mm when measuring from 50m away.

 

Monitoring the Growth of Cracks


When monitoring a bridge pier, cracks on the pier can be measured from a safe distance. Cracks can be monitored over time by comparing figures, thereby the
progression of damages such as the growth of cracks and the expansion of rust can be quantitatively analized.
Based on this analysis, it’s also possible to predict future deterioration.


  1. Developing new cracks
  2. Occurrence of efflorescence*
    (The decalcified aggregate concrete which appears on the surface of the pier)
    *It may present a cosmetic problem only, but can sometimes indicate serious structural weakness.
  3. The growth of a crack 1st: Length 200mm/Width 0.1mm → 2nd: Length 340mm/Width 0.25mm