Geokon 4422, Instruction Manual

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2.2 Crackmeter Installation
The Monument Crackmeter is provided with threaded rods that can be either grouted in short
drill holes or epoxied to the surface. It will normally be found more convenient to fix the cable in
place before the crackmeter is attached.
The crackmeter may be installed at its midrange position by leaving the metal pin in (see Figure
1 and Figure 2 in the following subsections) or the pin may be removed, allowing the initial gage
reading to be set for the anticipated direction of movement. When setting the gage position using
a portable readout, use the reading ranges in Table 1 to determine the proper position.
Approximate Midrange
Reading
Approximate Reading to
Measure Extensions
Approximate. Reading to
Measure Compression
4500-5000 2500-3000 6500-7000
Table 1 - Crackmeter Reading Ranges
2.2.1 Drill Hole Type
For the standard range crackmeter (4 mm), drill two 9 mm (3/8”) diameter holes,
spaced 110 mm (4 3/8”) apart, to a depth of 25 mm (one inch). A drill-hole-spacer-bar
is provided to make this easier. Drill one hole then place a slightly smaller drill in the
hole and use the spacer bar to locate the second hole.
Screw the two stainless steel studs onto the threaded rods, fill the drill holes with epoxy
or quick setting cement, and push the studs into the grout or epoxy with the metal pin
holding the crackmeter at the midrange position still in place. When the grout or epoxy
has hardened then the metal pin can be removed.
Figure 1 - Model 4422-1 Monument Crackmeter, Groutable Anchor Type