XY Mechanical Stage 50x50mm for Microscope

During measurement, first place the object to be measured on the center position of the field of view of the stage, adjust the clear image, open the crosshair, and then move the object to be measured to the starting position to be measured, so that the center intersection of the crosshair is aligned with the said position, turn on the scale 0 position (or note the reading position), then move the object to be measured in the X or Y direction until the end point of the measurement position, then stops, and finally read through the measuring scale.

Measurement error in XY horizontal direction
During measurement, aim at the starting point of the object to be measured through the eyepiece or the cross positioning on the display, then move the stage, so that the stage is moved to the end point in the horizontal axial movement. At this time, it is necessary to ensure that the distance between the two points is the actual distance of the horizontal direction. If the stage is tilted, an angle is created between the horizontal direction and the tilted or oblique direction. The numerical value we read is actually the length of a diagonal line, thereby causing error.

For XY stage measurement, it is necessary to use a high-magnification objective as much as possible.
The objective lens has a certain depth of field. The smaller the objective lens is, the larger the depth of field will be. The large depth of field cannot reflect the image blurring conditions caused by the up and down misalignment when the stage moves horizontally: the bigger the objective magnification, the smaller the depth of field. When the stage is not flat and moves out of the depth of field range, the image will be out of focus and becomes blurred, indicating that the stage is in a non-horizontal position, and the accuracy of the measurement at this time will be higher.
In principle, the depth of field range of the objective of the microscope is the minimum error range of the flatness of the platform stage.

For XY horizontal measurement, when measuring objects with shorter lengths, this error is very small, even negligible. If the measured object is relatively long, the bigger the angle at which the stage is tilted, the greater the differential value between the oblique line of the measured image and the actual horizontal line segment of the object, and also the bigger the accumulated error will be.
Because big stage has a bigger accumulated error, when measuring a relatively bigger length, it is necessary to calibrate the error within the stage system in advance. In measurement using computer software, the value of this accumulated error can be input into the measurement result for correction. Therefore, it must be ensured that the stage is always in a horizontal state in movement, which is the most basic requirement in optical measurement.

Ways to adjust the level of the XY stage:
1. Use a cross reticle in the eyepiece or display.
2. Select an objective with the largest magnification in the microscope system, and place a calibrated line ruler on the stage (a long transparent glass ruler for calibration). The marked front of the line ruler is below the ruler, near the side of the stage countertop.
3. Overlap the starting point of the line ruler with the starting position on one side of the stage; adjust the focus, ensure that the objective is aligned with the starting position image of the line scale to obtain the clearest image.
4. Move the X direction of the stage, so that the stage moves along the direction of the line ruler, and at the same time observe whether the grid image of the line ruler is clear, and record the blurred position of the image until the end position. After completion, do the side of the Y direction.
5. Among the above results, the unclear position is the position where the stage is not flat.

If the stage is unable to maintain horizontal, after the initial position is focus adjusted to get a clear image, the image will become more and more blurred, and in most cases, the stage is tilted to one side (up or down). To solve this problem, adjust the height of the four feet of the stage, or adjust the height position of the screws at the four corners of the bottom glazing of the stage center to keep the stage horizontal.
In general, adjusting the stage horizontal can adjust the height of the position of the anchor screw of the stage, or use a very thin shim (Shim) to adjust.
Sometimes, it is also necessary to adjust the perpendicularity of the optical axis of the microscope. Use the screw that fixes the microscope to top move the microscope, to make it shift in the vertical direction, keeping the microscope in a vertical position.

Using a line ruler can also calibrate whether the distance traveled by the line ruler at each grid value for measurement is consistent with the distance read by the stage drive (for example, the reading from the micrometer or the digital display), thereby calibrating the error of the stage movement accuracy. Such errors are often caused by the empty return of the stage drive or the insufficient of stage stiffness etc.
If line ruler is not used and the stage surface is observed directly, the above results can also be obtained. Also, when the stage surface is moved to each position, that whether the surface of the stage is uneven when processing can be displayed through clear or blurred image position, and can also observe whether the flatness of the stage plane itself is within the allowable range of the depth of field of the objective.