Stone hammer blow testing instrument mainly simulates the actual driving condition of the vehicle, and the individual parts of the vehicle body are often impacted by heavy objects such as sliding material and pavement gravels. Thus, the products are damaged. The product damage degree is determined by injection Angle, injection pressure, number of injection, airflow speed, the specification and quality of steel shot or gravel, impact duration and test instrument. 

Work Principles
A certain weight of gravel is bounced into the feeder by vibration. Due to the vacuum formed by the high speed air flow in the lower part of the feeder, the collision medium is sucked into the ejection gun assembly, and then is shot into the test sample by the jet stream. After the medium hit the test target, the medium falls into the gravel collecting box. The test machine causes a large number of steel balls or rubble with sharp edges to hit the sample surface in a short time. The whole experiment is carried out under a controlled temperature. After the impact is finished, the loose coating is removed with adhesive tape to reveal the residual stone strike marks on the sample, which can be used to judge the performance of the resistance to stone impact by analyzing the damage degree of the sample.

Standards
SAE J400,VDA 621427,ISO 20567-1,ASTM D3170,GMW14668-3.4.9,Peugeot/Citroen D241312,Chrysler 463PB-52-01 ,Chrysler 463PB-39-01,Mazda MES MN 601C ,Toyota,Nissan,Ford BI 157-04,Ford BI 157-05.

Features
· The ejection nozzle is free and fast, complying with standards such as VDA and SAE.
· The touch screen setting makes the test process more convenient and concise.
· Plate type test sample angle can meet the requirements of 0-90 ° settings at 15 ° intervals.
· Continuous or intermittent operation can perform multiple tests in a short time.
· Feed rate is adjusted by electromagnetic vibration feeder.
· The large volume compressed air storage tank keep pressure and flow constant while controlling the pressure through control valve in the ejection nozzle.
· It is equipped with various safety protection measures: safety power-off device, air pressure safety protection device, which conforms to European CE and EMC certification.

Assessment Method
1) Stick the adhesive tape to the surface of the sample coating, apply uniform force for tight attachment to the surface of the sample and avoid creating air bubbles. Then pull up the tape.
2) The tape is attached to the surface of the sample coating, and it is applied to the surface of the sample with uniform force to avoid the bubbling. Then pull up the tape from the opposite direction of 1).
3) Repeat the steps of 1) and 2) until the damaged coating completely comes off.
4) At this pint, you can accurately count the damage points for assessment.
5) Cover the transparent grille on the sample, count the number of coating damage points (except the impact marks) in 101.6mm x 101.6 mm area and confirm the size of the damage pints.

Technical Parameters