Zero Error Calibration
1) Zero Error Calibration of horizontal position
After the bubble is stable, read a at one end of the bubble in the horizontal position, then turn horizontal ruler to 180 degrees and place it in the original position of the plate, write down the reading B at the other end of the bubble on one side of the first reading, and half of the difference between the two readings is the zero error.
2) Zero Error Calibration of vertical position
Adjust universal dividing head to align one end of the bubble in the horizontal position with the long engraved line, turn universal dividing head to 90 degrees, and read c at the corresponding end of the bubble in the vertical position, adding c to the zero error of horizontal position is the zero error of vertical position.
3) Zero Error Calibration of 45 degree position
Adjust universal dividing head to align one end of the bubble in the horizontal position with the long engraved line, turn universal dividing head over 45 degrees, and read d at the corresponding end of the bubble in the 45 degrees position, adding d to the zero error of the horizontal position is the zero error of the 45 degree position.
Index Error Calibration
Rotate universal dividing head to align the bubble with the starting line on the left (or right) of the horizontal bubble, and then change the indication value of universal dividing head in sequence. Each change is the nominal division value of horizontal ruler. After the bubble stabilizes, read at one end of the bubble
Calibrate the other side of the level bubble in the same way. The error of the dividing value is calculated as follows:
In the formula,
The division value error of horizontal ruler, lattice;
A reading of horizontal ruler.
According to the above method. The error of dividing value of horizontal position blister, vertical position blister and 45 degree position blister can be calibrated respectively.
