Electronics Black Wrist Watch
Electronics Black Wrist Watch

R-4 – Magnetic Probe Extensometer / Settlement

Category: Geotechnical & Civil Engineering Instrumentats

VERSATILE

EASY TO USE

MAGNETIC REED SWITCH PROBE

The R-4 is used to manually measure settlement or heave of soils at various depths, allowing the end user to create settlement/heave.

 

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The R-4 consists of a magnetic reed switch mounted on a graduated tape and reel. The switch is activated by magnetic targets installed at different elevations along an access pipe in a borehole or within an embankment or fill.

 

The R-4 detects the position of the magnetic anchors outside the riser pipe when it is lowered down the access pipe. The probe is suspended by a single graduated tape that incorporates the electrical leads. The tape graduation is used to determine the probe’s precise position relative to the magnets. Comparison of these locations allows heave and settlement determination.

 

The magnetic anchors are available in three configurations: leaf spring anchor for borehole installation, plate anchor for embankment or fill installation and datum magnet that is fixed directly to the bottom section of access pipe. The leaf spring anchor can be pushed in place or lowered with the access pipe and released with an external draw wire.
The plate magnet is a plate with a central hole. The plate magnets are installed over the riser pipe and between the layers of placed fill, as the filling operation proceeds.

 

Telescoping couplings are used where deformations exceeding 1% are expected.TheR-4system is compatible with standard inclinometer casings. The use of a probe centralizer is recommended for repeatable readings.

 

Specifications

 

Probe:  Stainless steel, 14.3 x 227mm

Cable:  Epoxy coated steel tape with medium density polyethylene jacket

Metric cables have 1mm graduations and imperial cable have 0.01ft graduation
 

Reel:  263 or 300mm in diameter depending on cable length
 

Battery:  The readout operates on with one 9-Volt alkaline cell.
 

Material: Magnet body in  PVC
 

Temperature range: -30°C to +80°C
 

Plate magnet dimensions: 200 x 200 x 9.5 mm standard, 300 x 300 x 9.5 mm optionnal
 

Access tube:   -Standard 1’’ pipe sch.80 flush-coupled PVC pipe (33mm)

(telescoping sections available if large settlementss are anticipated)

– 70mm or 85mm inclinometric casing

– optional 1.5” pipe sch.80 flush-coupled PVC pipe (48mm)

 

  DATUM RING MAGNET  
  Model No.   Casing
  FR-1131A50300     33mm
  FR-1131A50300C   48mm
  FR-1131A50300A   70mm
  FR-1131A50300B   85mm

 

Note: Probe with 100 or 300ft of cable also available

Readout Unit and Magnet model

 

  READOUT UNIT (probe and reel)    
  Model No.   Cable length   Resolution
  FR-1013E50100A   30m   1 mm
  FR-1013E50100B   50m   1 mm
  FR-1013E50100C   100m   1 mm
  FR-1013E50100D   150m   1 mm

 

 

  LEAF SPRING MAGNET      
  Model No.   Min. borehole diameter   Released Outside diameter   Casing
  FR-1131A50100   101 mm   222 mm    33 mm
  FR-1131A50100C   101 mm   254 mm    48 mm
  FR-1131A50100A   127 mm   279 mm    70 mm
  FR-1131A50100B   152 mm   305 mm    85 mm

 

 

  PLATE MAGNET  
  Model No       Casing
  FR-1131A50200   33 mm
  FR-1131A50200C   48 mm
  FR-1131A50200A   70 mm
  FR-1131A50200B       85 mm

 


Ordering Info

 

Please specify:

  •     Borehole diameter and depth
  •     Access tube model and length (For more information about 70 and 85 mm O.D. access tube, please refer to standard inclinometer casing data sheets)
  •     Telescoping section
  •     Anchor model number
  •     Readout instrument model no.

 

Optional accessories:

  •     Probe centralizer
  •     Collar tape guide