KNOWLEDGE
水平器の知識
What is a vial?
Its structure is, formed to a drum shape with needed radius, and then enclosed liquid leaving a suitable size of bubble. It is convenient for eye measurement of a bubble position with benchmarks of inside or surface of a case. The bubble moves inside the vial in proportion to its horizontal degree. When the bubble reaches the midpoint of the benchmarks, it shows the horizontal. As its feature, it is ideal to check the horizontal degree or an inclination of one way.
| Lines | Shapes | Features | Vial |
|---|---|---|---|
| 2-line |  |
Shows the horizontal when a bubble reaches the midpoint of the lines. |  |
| 4-line |  |
Shows the horizontal when a bubble reaches the midpoint between inner 2 lines. Width between an inner line and an outer line is 2mm. It can be used to fix an aim when measuring the horizontal or making a certain measurement of a gradient in general use. |  |
| 5-line |  |
When a bubble is in the widest space, the horizontal is shown. When a bubble comes the edge of each benchmark, it shows indicated gradient. |  |
| 6-line |  |
When bubble reaches the midpoint between the most inner lines, it shows the horizontal. When bubble reaches second inner line, it shows the gradient of 1/100. When bubble reaches the outer benchmark, it shows the gradient of 2/100. |  |
What is sensitivity
Sensitivity is, by the definition of JISZ8103, the degree which a certain measuring instrument feels for change of the measured amount; in other words, the ratio of a change of indicated amount to a change of measuring amount on a certain amount of measurement.
Precision of a vial?
Precision is, by the definition of JISZ8103, a reading of a certain measuring instrument, or a comprehensive satisfactory performance including accuracy and precision (minimized dispersion in the values of measurement).
The true value for the purpose of measurement (design value) is included in measured value±precision (comprehensive error by the accuracy and the precision of a measurement result).