Schmidt OS-120 Pendulum Hammer

Schmidt OS-120 Pendulum Hammer

Concrete, Materials, Components

Schmidt OS-120 Pendulum Hammer

Schmidt OS-120 Pendulum Hammer
Schmidt OS-120 Pendulum Hammer
Schmidt OS-120 Pendulum Hammer

Schmidt OS-120 Pendulum Hammer

The Schmidt OS-120 Pendulum Hammers are designed to test on softer material such as light weight concrete, gypsum boards, fresh concrete and the mortar of joints in brickwork. Their unique design allows easy to handle measurements on vertical and horizontal surfaces.

Schmidt OS-120 is the only rebound hammer worldwide working with the pendulum system, thus it must not be loaded on the test surface. The larger plunger surface on the Schmidt OS-120PT allows tests on soft concrete starting with a compressive strength of 1 MPa.


  • Pendulum type rebound system
  • Large, half circular scale with high resolution
  • Two different plunger types adopted to the different applications


  • Assessment of light weight concrete, gypsum boards and fresh concrete
  • Assessment of the mortar quality of joints in brickwork


The rebound number is determined on the basis of the following standards:

  • EN12504-2 (Europe)
  • ASTM C 805 (North America)
  • JGJ/T 23-2011 (China).

Schmidt OS-120PT:

For the creation of user defined conversion curves, we recommend the procedures described in EN 13791 (Europe), ASTM C805, ACI 228.1R (North America), JGJ T23-2011 (China). (Applies to Schmidt OS-120PT only.)


Austrian Guideline for tunnel lining, published December 2012. Austrian Construction Association. (To determine the time for formwork removal during tunnel construction). Applies to Schmidt OS-120PT. TNO Report BI -88-009/61.8.2060-VOE from IBBC Delft Netherlands (Mortar joint testing). Applies to Schmidt OS-120PM.

Technical Data

Schmidt OS-120PTSchmidt OS-120PM
Measuring range1 N/mm2 (145 psi) -
5 N/mm2 (725 psi)
Classification of brickwall mortar from Poor - Excellent
Impact energy0.833 Nm (0.614 lbf)
Hammer mass720 g (1.59 lb)665 g (1.47 lb)
Hammer head diameter40 mm (1.57“)8.0 mm (0.315“)
Weight3.45 kg (7.60 lb)
Dimensions of housing230 x 60 x 200 mm (9.06“ x 2.36“ x 7.87“)
Operating temperature-10 to 50°C (14 bis 122°F)
Storage temperature-10 to 70°C (14 bis 158°F)
DYWIDAG-Systems International GmbH

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