Use of strip level

When using a level for measurement, it is necessary to understand the relationship between the positive and negative readings of the level and the direction of inclination, and then select a reference line for reading. (1) Determination of the positive or negative value of the reading: The positive or negative value of the level’s reading is determined by the direction in which the bubble moves and the direction in which the level itself moves. If the directions of the two are the same, the reading is positive, indicating that the surface being measured slopes upward ； If the directions of the two are opposite, the reading will be negative, indicating that the surface being measured is inclined downward. (2) Selection of the reading reference: There are two references for level gauge readings. The first is to take absolute horizontal readings, which are made using the zero line of the level gauge as a reference; the resulting value indicates the height difference due to the inclination of the surface in question relative to the natural horizontal plane over a certain distance (the level gauge must be properly adjusted to its zero position), or it represents the angle of inclination of that surface relative to the natural horizontal plane ； The second is to read the value on a relative scale; in this case, the reading indicates the angle of inclination with respect to the selected reference direction on the side, or the height difference over a certain length due to the inclination with respect to the selected reference method. (3) Reading method 1. Grid counting method: a. Using the zero line as a reference, count the number of grids between either end of the bubble and the zero line; this value represents the reading of the level. This method is simple and commonly used. b. Using the scale line where the starting position of either end of the bubble lies as a reference, count the number of grid units that end is away from this reference scale line; this value represents the reading of the level. c. Starting from either end of the bubble and using the point where it is close to a scale line as a reference, count the number of grid lines separating that end of the bubble from this scale line; this value represents the reading of the level. This reading method eliminates reading errors caused by changes in bubble length due to temperature errors, and is commonly used in precision measurements. I found it online; I’m not sure if yours is of the same quality

Is your method correct? A strip level can already be used for direct reading; so what’s the need for using a feeler gauge?

First, calibrate the level; then take a horizontal reading at the same position (using a feeler gauge). Next, turn it 180 degrees and take another measurement. If the direction of inclination is the same and the readings are identical, it proves that the levelness of the measured plane is 0.1 mm/200 mm. (200mm is the horizontal length of the strip specimen).

If your level is 1M, you are correct.