The new Elcometer 224 – the digital device for estimating the surface profile
12.03.2019
From launching in 2012 series of questions have been raised on how to correctly use the Elcometer 224.
The recommended technique implies making at least 10 measurements at the level of the surface and recording their average. The way in which the device was initially designed created the wrong impression that one measurement would be enough for a proper estimation of the surface profile.
The subject was intensively discussed in the Standard Committees especially at ASTM (American Society for Testing and Materials) and AS (Australian Standard) and the conclusion was that 10 measurements are needed for an accurate result. ASTM considers that the user can take into consideration either the average of all measurements, or the highest level for determining the profile. SANS (South African National Standard), on the other hand considers that 5 measurements would be enough.
Elcometer incorporated all above mentioned aspects and adapted the device accordingly.
New measurement ways
Elcometer 224 offers now the possibility to choose a way of effecting the measurements “immediately”, “personalized” and “standard”, so that the operator can choose what best suits him according to the standard in force.
The immediate mode allows the user to organize individual measurements that are displayed on the screen (for B&T models) and saved in the memory of the data group (for the T model). This way of measuring allows using the device as initially.
The personalized mode allows the user to organize 5 or 10 measurements. Their levels are displayed on the screen (for B&T models) and their average, the minimum and the maximum levels are saved in the memory of the data group (for the T model).
The standard model allows organizing the measurements according to the following standards: AS 3894.5, ASTM 4417-B, and SANS 5772.
AS 3894.5 (Australian Standard)– The user has to organize 10 measurements. The lowest 5 levels of them are going to be eliminated and the average of the other 5 will be displayed on the screen (for B&T models) and saved in the memory of the data group (for the T model).
ASTM 4417-B (American Society for Testing and Materials)– The user is supposed to organize 10 measurements and can opt for displaying them on the screen (in case of B&T models) or for saving (for the T model) their average level or the maximum level.
SANS 5772 (South African National Standard)– The user is supposed to organize 10 measurements and their average level will be displayed on the screen (for B&T models) and saved in the memory of the data group (for the T model).
Modifications in regard to the calibration methods
When the new measuring methods have been introduced, the calibration ones have also been reviewed modified and simplified. Elcometer 224 – T model includes now the following calibration methods:
Zero calibration – the calibration can be used for both T and B models.
Calibration in 2 points –which is more precise than the Zero Calibration.
Calibration on the measurement point
