Types of EDM instruments

1. Microwave System

2. Make use of Microwave

3. Such instruments were invented as early as 1950 in South Africa Dr. T.L Wadley and named theam as Tellurometers.

4. The instruments need only 12 to 24 V batteries

5. There are light and highly portable.

6. Tellurometers can be used in day as well as in night.

7. The range of these instruments is up to 100km

8. It consists of two identical units. One unit is used as master unit and the other as remote unit.

9. Electro-Optic or light wave System

10. These type of instruments was first developed in Sweeden and was named as Geodimeter.

11. During night its range is up to 2.5 km while in day its range is up to 3km

12. Accurancy of these instruments varies from 0.5 mm to 5mm / km distance

13. These instruments are also very useful for Civil Engineering Projects.