What are the three aspects of error analysis of the identification test machine?

As a high-precision detection device, the test machine focuses on the measurement accuracy when using it. However, according to the JJG139-1999 verification regulations of the test machine, its allowable error is usually not more than ±1%. The following is the way to reflect the error of the test machine provided by Jinan Hengsi Shengda Instrument Co., Ltd., I hope that users will pay attention to it in their work:

1. The positive deviation of the display value exceeds the difference.

After confirming that the installation level of the instrument meets the requirements of the regulations, first check whether the friction in the working part is too large. If so, the guide wheel clearance should be adjusted to eliminate friction. If necessary, clean the working oil cylinder. If there is still a positive difference after eliminating the influence of friction, the tightening screws of the swing rod in the force measuring part (reading mechanism) and the push plate connecting the shaft sleeve should be loosened, and the push plate should be adjusted to the inside. After tightening the tightening screws, the small disc is checked step by step, and repeated several times until the calibration is passed. If the small disc is qualified and the large and medium discs are still exceeding the difference, the weight of B and C thallium should be appropriately increased until the calibration is passed.

2. The negative deviation of the test machine shows the negative deviation exceeds the difference.

First, check whether the force-testing piston is installed correctly and whether the friction is too high. After this reason is eliminated, adjust the push plate to the outside and adjust the small dial to be qualified. If the large or medium dial is still exceeding the difference, the weight of B and C thallium should be appropriately reduced until the calibration is passed.

3. The display error shows "positive front and negative afterwards" or "negative front and positive afterwards" on the dial and some points exceed the difference.

At this time, the angle of the contact surface between the push plate and the tooth rod head should be changed. The contact surface of the universal test machine is usually fixed to the surface of the push plate with a flat steel sheet through two upper and lower screws. The adjustment method is to loosen the two screws, and use copper or other thin metal sheets to pad the upper or lower side between the steel sheet and the push plate (only pad on one side), so as to change the angle, and repeatedly check and adjust until it is qualified.

More technical information of test machines are available at Jinan Hengsi Shanda Instrument Co., Ltd.