VDA Stone Hammer Blow Test Instrument,
MULTI GRIT TESTER 508 VDA
Purpose and Application
The MULTI GRIT TESTER 508 VDA is a stone hammer blow testing instrument that at first was developed in co-operation with the "Verband der Automobilindustrie (VDA)" (Association of the Automotive Industry) but now also meets the specifications of national and international standards.
The MULTI GRIT TESTER 508 VDA is used to assess the ability of single and multiple layers of paints and similar coating materials to stand up to the impacts caused by small bodies of low mass hitting the specimen at high speed as experienced on road and rail vehicles and other equipment used in the transport field.
Principle of the Test
A defined number of impact bodies of specified shape, material and surface quality is made to impinge for a given period of time and with a defined energy at a determinate angle (54° in accordance with DIN/ISO) of impact onto the specimen.
Design and Mode of Operation
The MULTI GRIT TESTER 508 VDA is a multi-blow test instrument of high precision, and its special feature is the good repeatability and comparability of the test results obtained.
The specimen is subjected to impacts by sharp-edged steel shot accelerated by compressed air. An air accumulator in the system eliminates effects of momentary pressure variations in the external compressed air supply.
The shot is entered automatically using an adjustable vibratory feed. On a multifunctional display the working pressure, the duration of the test, the setting of the vibratory feed and the number of tests conducted (total / temporary) can be read off alternatively.
To facilitate working with the MULTI GRIT TESTER 508 VDA the instrument is available - upon request - with a pneumatic specimen applying device.
- 508 VDA
- DIN EN ISO 20567-1
- FORD FLTM BI 157-06
- RENAULT D24 1702
- PSA D24 1312
- DAIMLER DBL 5416
Dimensions (W x D x H): 1750 x 500 x 1220 mm
Weight (net): approx. 100 kg
Compressed air connection: min. 6 bar / max. 10 bar, requires connecting hose with ID 13 mm
Filling pressure control: approx. 5 bar, factory set
Working pressure: (0 - 3) bar / quality class I
Time for feeding shot: (5 - 30) s / adjustable
Display: 8 digits, lighted LCD, height of digits 11.5 mm
Power supply: 85-264 VAC / 47-63 Hz(control circuit volt. 24 V)
Shot (Steel shot acc. to VDA): GH Diamant 06302, sharp-edged (3.5 - 5 mm)
Note: By now many users also apply further types of shot material, e. g. in accordance with the specifications of different international vehicle manufacturers or internal specifications based on experience in their own company.
Ex. Steel Shot (2.0 - 2.8 mm) GH-K Diamant (for shot test acc. to Daimler DBL 5416) available on request
Rating by means of reference images according ISO 20567-1
Most standards including ASTM and ISO describing for evaluation of results a visual comparison of samples with reference images and/or manual counting of impacts
Available on request :
Set of Calibration Sandwiches for Model 508 VDA, consists of:
- 10 calibration sandwiches 100 mm x 200 mm (each 1 x white cardboard with already pre-printed legend form,
- carbon paper and clear PVC foil ~150 μm)
- and 1 plate of stainless steel (100 mm x 200 mm x 1 mm)
Please note, that the execution of the Calibration Sandwich differ a little bit from the recommendations of the EN ISO 20567-1:2006 (E) standard:
- we use some white cardboard instead of the recommended white paper
- we use some PVC foil (~150 μm) instead of the recommended PE foil (150 - 200 μm)
But, however, as you know we are since a lot of years the manufacturer of this kind of testing machine and the current specification of the Calibration Sandwich is a result of our long lasting experience in this field.