The objectives of this research are to design the load cell tolerance testing machine and demonstrate the tolerance of load cell with a tolerance test that has a beam length of 90 cm. It can create the compressed force at the load cell more than 1 kN The experiment cam be divided into 2 stages; 1.) verification of load range and 2.) linearity test. Both stages are tested at a temperature at 25°C using 10 to 30 kg of mass in the lowest compressed force condition of 0.091 kN and the maximum compressed force condition of 1.12kN As a result the linearity performance of the tolerance of the load cell test kit between calculated force and displayed value force are different 0.354 percentage only while the standard deviation of displayed value force and voltage signal output are 0.0013 and 0.0022 respectively. It reveals that the experimental result is reliable because of less than 1. In addition the tolerance of the load cell tolerance testing machine is 0.00300 (0.3 percent) which was calculated from the comparison of the tolerance specification of two main equipment that specified by manufacturer.

This research aims to study and compare the test results obtained from the rolling resistance tester of automobile tires based on force method and torque method system. The four newly manufactured tires were sampled from two tire classes namely passenger car tires (Class C1) and light truck tires (Class C2). The tire rolling resistance test according to the international standard UN ECE Regulation No.117 was used as an important research process. The experimental work discovers that the rolling resistance of the same tire obtained from the test between the two different methods of testing machines was not more than 6 percent different. The testing results that used the torque method system calculation are high reliability because of the principle of calculation from the measurement value directly results in. and suitable for research testing. However the force method tester can perform more than a tire simultaneous test which is suitable for working in industrial applications where time is limited.

The objectives of this research is to study the relationship between tolerance and measurement range of load cells. Tolerance test kit length of mass beam 90 cm was used. It can create the compressed force at the load cell more than 1 kN. The experiment cam be divided into 2 stages; 1.) verification of load range and 2.) linearity test. Both stages are tested at a temperature at 25°C using 10 to 30 kg of mass in the lowest compressed force condition of 0.091 kN and the maximum compressed force condition of 1.12kN As a result the linearity performance of the tolerance of the load cell test kit between calculated force and displayed value force are different 0.354 percentage only while the standard deviation of displayed value force and voltage signal output are 0.0013 and 0.0022 respectively. It reveals that the experimental result is reliable because of less than 1. In addition the tolerance of the load cell tolerance testing machine is 0.00300 (0.3 percent) which was calculated from the comparison of the tolerance specification of two main equipment that specified by manufacturer.

The objectives of this research are to study the rate of deterioration of tyre friction coefficient and investigate the quality of new and old tyres that are currently in use. A set of the rolling resistance testing was designed and set up to work with the single dynamometer according to speed 80 km/h tire load 4660 N and inflation pressure 30 psi. There were three tire samples new tire one year used tire and two year used tire to find the rolling resistance coefficients. The finding shows that the rolling resistance was inverse variation with tire aging. For instance the new tire (1st sample) had the highest rolling resistance on the other hand the two year used tire (3th sample) had the lowest rolling resistance. Moreover the rolling resistance coefficients were inverses variation with tire aging. Besides the one year used tire had the average of the decreasing rate of the rolling resistance coefficient at 0.03689 N/kN per a week while the two year had the average of the decreasing rate of the rolling resistance coefficient at 0.03671 N/kN per a week. Furthermore the result also revealed that the rolling resistance coefficients nonlinearly decreased comparing to the tire aging.

Nowadays brake pad is a one of products that plays a role in the automotive parts industry and directly affects safety. Therefore there are many designs of brake pad for product development. The technique of reinforcing the layer in brake pads is another option for developing such products. The objectives of this research are to solve the problem of noise from brake pads using the material layer reinforcement technique and raise the quality of brake pads to use in the industrial sector. As a result the prototype brake pads with reinforcement techniques by means of damping layer were performed. Consequently the experimental work reveals that the brake pads with damping layer technique for brake pads can reduce vibration and also brake noise at the same frequency at less 10 percent at braking speeds of 50 100 and 130 km/h. Besides this technique can be applied to the production of brake pads in the same formula. However the prototype brake pads is still in the product development phase for testing in a variety of conditions both temperature factors and usage period