
MODEL 4420 VIBRATING WIRE CRACKMETER
| INSTALLATION |
3
The weldable fixture is designed to aid in mounting the crackmeter on steel
members. The machine bolt expansion anchors and groutable anchors are used
to install the crackmeter on concrete or rock. The anchors are installed at the
appropriate spacing distance, depending on the anticipated direction of
movement (extension or compression). Refer to the table below.
3:
FIGURE 3:
Anchor Types with Dimensions
Section 2.2.2 through Section 2.2.4 contain detailed instructions on each type of
anchor. Section 2.3 contains special instructions on the following models:
■
4420-1-3 mm (.125")
■
4420-1-12.5 mm (.5")
■
4420-1-25 mm (1")
TABLE 1:
Crackmeter Anchor Spacing Distances
When setting the gauge position using a portable readout, use the reading
ranges in the table below to determine the proper position.
TABLE 2:
Crackmeter Reading Ranges
Be sure to consider the following:
■
Note that the calibration sheet (see Figure 12) supplied with the crackmeter
shows factory readings at zero, 25%, 50%, 75%, and 100% of the range of
extension.
■
These readings can be used as a guide to set the crackmeter in any part of
its range, either in anticipation of closure or opening of the crack.
■
Extend the crackmeter until the desired reading is obtained.
Model & Range
1:
Midrange
To Monitor Extension
To Monitor Compression
4420-3 mm (.125")
292.6 mm (11.52")
291.1 mm (11.46")
294.1 mm (11.58")
4420-12.5 mm (.5")
317 mm (12.5")
310 mm (12.2")
325 mm (12.8")
4420-25 mm (1")
343 mm (13.5")
330 mm (13")
356 mm (14")
4420-50 mm (2")
396 mm (15.6")
371 mm (14.6")
422 mm (16.6")
4420-100 mm (4")
554 mm (21.8")
503 mm (19.8")
605 mm (23.8")
4420-150 mm (6")
645 mm (25.4")
569 mm (22.4")
721 mm (28.4")
4420-200 mm (8")
869 mm (34.2")
767 mm (30.2")
970 mm (38.2")
4420-300 mm (12")
1186 mm (46.7")
1034 mm (40.7")
1339 mm (52.7")
Note for Model 4420HT: Due to the U-joint configuration of 4420HT, the overall gauge assembly length is increased by 35
mm (1.375"). This length should be added to the anchor spacing distance shown above.
Approximate Midrange Reading
2:
Approximate Reading to Monitor
Extensions
Approximate Reading to Monitor
Compressions
4500-5000
2500-3000
6500-7000