The formulae used in the compressive strength correlation curves in the OS8000 and OS8200 rebound hammers can be found in the Schmidt Hammer Conversion Curve Database below:

The formulae used in the compressive strength correlation curves in the OS8000 and OS8200 rebound hammers can be found in the Schmidt Hammer Conversion Curve Database below:

Here it is necessary to differentiate between classical rebound hammers (R-value) and the Silver Schmidt hammers (Q-value). Classical rebound hammers require an impact angle correction when the impact is not carried out...

Here it is necessary to differentiate between classical rebound hammers (R-value) and the Silver Schmidt hammers (Q-value). Classical rebound hammers require an impact angle correction when the impact is not carried out horizontally. For the Original Schmidt, the correction can be found in the manual for vertically up and vertically down measurements. The Original Schmidt OS8000 applies a more advanced impact angle correction automatically for any angle. On the app, the user can see both the uncorrected and the corrected values. The Silver Schmidt hammers are intrinsically impact angle independent so no correction is necessary.

There is no simple answer to this question.
The answer depends on the region you are in and the standards you are working to. In China for example there are standardized correlation curves, which may be selected in the...

There is no simple answer to this question.
The answer depends on the region you are in and the standards you are working to. In China for example there are standardized correlation curves, which may be selected in the Original Schmidt Live app. Other regions such as Korea and Japan have nationally accepted correlation curves that are widely used. These may also be programmed directly into the Schmidt Live app and used. However, unless the standard you are using provides a method to use standardized curves then you should always calibrate your hammer to the concrete under test using a custom materials curve. If this is not possible we recommend using the lower 10th percentile curve with the Silver Schmidt OS8200 hammer to give a conservative estimate. This is a safer option with a smaller chance of overestimating the strength. Another option is to use the EN13791 screening test with either Original Schmidt OS8000 or Silver Schmidt OS8200 which again gives a conservative estimate. The use of custom material curves is fully explained in the tutorial "12. Custom materials" included in the Original Schmidt Live app.

In order to create a custom materials curve, it is necessary to record rebound values at a number of locations in the structure where cores will be taken. Alternatively, rebound measurements can be made on standard cubes...

In order to create a custom materials curve, it is necessary to record rebound values at a number of locations in the structure where cores will be taken. Alternatively, rebound measurements can be made on standard cubes or cylinders which are then crushed in the press to determine the actual compressive strength. This data is then used to create a custom material curve using a simple spreadsheet function. The complete procedure is explained in the tutorial video "12. Custom materials" included in the Original Schmidt Live app.