• Identification of different types of levelling Instrument
The list of different types of levelling instrument is given below – 1. Dumpy Level 2. Cook’s Reversible Level 3. Cushing Level 4. Wye Level 5. Modern (tilting) Level 6. Automatic Level 7. Digital Level 8. Hand Level
• The most used level instruments are:
1. Dumpy Level 2. Modern (tilting) Level 3. Automatic Level
• Benefits of Dumpy Level Compared to Wye Level
1. Structurally strong, simple and lovely. 2. The number of temporary parts is less. 3. Less co-ordination is required. 4. Adjustment is long lasting. 5. The number of consuming losses is less. 6. The cost of construction and repair is less.
• Disadvantage of Dumpy Level Compared to Wye Level
1. The telescope cannot be separated. 2. The telescope can not rotate the vertical axis. 3. Re-adjusting is difficult.
• Different Parts of Levelling Instrument:
1. Telescope i. External Focusing Telescope ii. Internal Focusing Telescope 2. Objective or Object Glass 3. Eye Piece i. Erecting Eye Piece ii. Inverting Eye Piece 4. Diaphragm 5. Diaphragm Screw 6. Focusing Screw
7. Optical Sight
8. Ray Shade 9. Level Tube 10. Levelling Head
11. Bottom Plate 12. Tripod, etc.
• Term Related of Levelling Instrument:
1. Line of Collimation 2. Axis Of Telescope 3. Axis of Bubble Tube 4. Vertical Axis 5. Height of Instrument 6. Plane of Collimation 7. Focusing i. Eye Piece Focusing ii. Object Focusing 8. Parallax