What errors should be avoided in the use of the microscope
When using the reading microscope, care should be taken to avoid large human errors in reading, which may easily cause visual errors.
1. Parallax: The parallax of an optical measuring instrument is due to the fact that the image of the measured object is not in the same plane as the ruler for measurement, so when the observer's eyes move, there will be a relative displacement between the image and the ruler.
The reading microscope consists of an eyepiece and an objective lens. The marking line is located between the eyepiece and the objective lens. In order to eliminate parallax, the eyepiece should be adjusted first to make the image of the crosshair clear, and then the lift knob should be adjusted to make the image of the object to be measured clear. Move your eyes , if there is no relative displacement between the image of the measured object and the crosshair image, it means that they are in the same imaging plane.
2. Pitch error: Since there must be a gap between the inner thread and the outer thread of any helical measuring device, the readings corresponding to different rotation directions must be different. This difference is called pitch error. Therefore, when using a reading microscope for length measurement, the crosshairs should be advanced in the same direction, aligned with both ends of the object to be measured, and do not go backwards in the middle, so as to eliminate the pitch error.
